Trick to Get Corners to Pull Up Charms Bar on Windows 8

Have you ever noticed how hard it is to pop up the charms bar on the shared edge of the screen (i.e. where the desktop crosses from one monitor to another) if you have multiple monitory on Windows 8? According to MSDN Windows 8 does impose virtual corners for these shared edges, but I still found the charms bar to be tricky to activate. Here’s how you can make it easier to activate the charms via corners on multiple monitors:

1. Right click on your desktop and select “Screen resolution” (above)

2. In the screen resolution pane, move one of your monitors slightly lower or slightly higher than the other. The more you move it down, the bigger your corner will be.

In this image, I now have a small, real corner on the lower right hand section of my primary monitor (monitor 1). That’s it!

Note that you only have a real corner on the bottom right of screen 1, the top right of screen 1 and all of the left side of screen 2 still relies on the virtual corners described here, however you do have one real corner you can rely on!

Windows Phone 7 Apps: Numbers from the last two years

Yesterday David and I released our first Windows 8 app, Movie Trivia. It’s been almost 2 years since David and I released our first app for Windows Phone, and since this is our tenth app I feel like now would be a good time to look back at our Windows Phone 7 app revenue and other numbers.

David and I started writing apps in November of 2010, writing apps in our spare time. It’s hard to estimate how much time we spent on our apps, but I’d guess that each of our apps took on average about 40 hours of work to make from start to finish, yielding a total of about 320 hours spent on our apps. Since January 2011 we have earned about $4500 from advertising revenue and app sales.  Most of this income was from 2011, when advertising revenue for our apps would earn us up to $50 a day. Since the heyday of March 2011, our advertising revenue has dropped enormously. Now our advertising and app sales revenue amounts to between $1-$2 a day.

Windows Phone 7 App Revenue and Other Statistics

Number of Apps 8
Total Downloads (appx.) 200,000
Total Paid Downloads (appx.) 430
$ Earned from Ads $4329
$ Earned from App Sales $168.66
Avg $ Per Month $204
Appx hours spent 320
Appx $/hr spent $14.06

Our top 3 most downloads apps are Name My Tune, Movie Trivia and Headshot. These are also the apps that have made us the most money. All of our other apps combined make about $0.50 a day. Our highest ranked app is Name My Tune, which has held the #3 spot among Music games for quite a while. In terms of downloads and rankings, I’d say we have done above average. We even managed to develop two apps that were deemed good enough to be featured in the Windows Store (Name My Tune and Headshot).

Yet despite this, our revenues have been below average. According to, the average revenue per app-month for Windows Phone apps is $1,234. Our average revenue per app-month is $25. I guess this means that David and I fall into the category of the 75% of Windows Phone developers that make between $0 and $500 per app-month [see p44 of the report above]. Admittedly several of our earlier apps were not very good. However, it’s difficult for me to understand why hits such as Name My Tune and innovative apps such as Headshot have not done well. Somebody once told me that the key to succeeding in the mobile world was to make good, polished apps, but after seeing Name My Tune and Headshot fail to generate decent revenue. One thing all of our apps lacked was good marketing. We didn’t spend enough time promoting our apps on various sites and advertising on platforms. If anybody has suggestions on how to go about this please leave a comment.

Nevertheless, I’ve learned tremendous amount about app development from this experience. In addition to the technical skills I’ve gained which have helped me both in my research and at work, I’ve also learned about the importance of thorough testing and driving apps to absolute perfection. When David and I released Babble, we thought it was pretty good and done. Now as I release Movie Trivia I have a long list of the extra features that I wish I could have added to make it perfect. That being said I think Movie Trivia is already pretty good and hope that it gets enough downloads for me to justify putting more time into it so that I can polish it further. I also have a much better understanding of how long it takes to write apps. It took me 3 weekends to make a good prototype of Headshot (good enough to demo in front of Windows Phone executives and win a contest), but it took me 2 months to convert the prototype into a good, popular product. Our list of apps chronicles our growth as designers and developers, every app was better than the last.

Due to research and work obligations, it is unlikely that David or I will be releasing more Windows Phone or Windows 8 apps in the near future. But who knows, maybe if Movie Trivia for Windows 8 or one of our other apps starts doing well, we will continue working on them. I for one would really like to improve some of our older games and polish off Movie Trivia. Even if we don’t make another penny, I hope I can find the time to do this.

If you found this article interesting and want to help us out so we continue making Windows Phone and Windows 8 apps, please try out Movie Trivia or any of our Windows Phone apps.

UIST 2012 Recap

Because I was an organizer for the UIST Student Innovation Contest this year, I spent much of my time running various errands rather than attending talks, an unfortunate byproduct of a fun, intense, and rewarding experience. While I will undoubtedly come up with a list of my favorite papers and posters after going through the proceedings, I feel like I cannot present a complete list right now. On the other hand, I did get to see a great number of student demos. As one of the judges for the contest I know how hard it was to pick the winners for most creative and most useful, and there were many great demos which I wish we could have awarded prizes to.

So this year I’m going to put a little twist on the recap and describe the great demos that didn’t quite win but which I thought were very interesting.

Pressure-sensitive helicopter. A very simple game of helicopter ( which I actually thought was a lot of fun to play. Pressure here really makes sense as a dimension.

Pressure-sensitive terrain editing. The idea here was similar to the PowerMice team (which won first place most useful). You could use pressure to deform terrain, with the goal of getting a bunch of animals to a farm. I thought the game was fun and I liked this very obvious use of pressure.

Using Pressure to change the probability distribution function of touch events. One thing I particularly liked about the entries this year were how many used pressure to disambiguate otherwise ambiguous selections. Team Glasgow did an especially great job with this, they used pressure to modify the probability distribution function of the touch event. The basic idea was the harder you pressed, the more you indicated to the system “yes, I intend to select this”. They did this in the context of a mobile device, where lighter presses favored the prediction system, while harder presses favored the key at the touch location.

Using Pressure to select layers, and ForcePose. Two teams had quite similar ideas (and strong demos), which I actually thought were quite good. The idea was to use pressure to select different layers on an interface. Tartan Touch demonstrated this in the context of an image editing program, whereas ForcePose used the same idea, but for Window selection. Both implementations were quite nice. I liked the way that Tartan Touch showed pressure feedback to give users an idea of which layer they were selecting, while I appreciated how ForcePose integrated the window selection directly into OSX.

Window manipulation using pressure. The last idea that I liked was window manipulation using pressure. The idea behind this was very simple, to use multitouch pressure gestures to resize, move, minimize and maximize windows. Their gesture set was three fingers low pressure panned, while three fingers high pressure moved a window. Similarly, pinching gestures lightly would zoom the content while higher pressure pinching gestures resized windows. I thought this was a really clever idea. Though admittedly I’m probably a bit biased because I presented a very similar idea last year.

Bonus: best contest video

We had the contest winners make a short video of their results. My favorite was from team Chimerical:

For more information on the contest winners and to see the rest of the videos, click here.

The History of 3D User Interfaces

I’ve been reading a fair amount about 3D user interfaces (aka “Spatial Input” aka “Natural Interfaces”) lately. Recent gaming technologies such as the Nintendo Wii, Playstation Move and Microsoft Kinect have brought 3D interfaces into the limelight, sparking plenty of innovation and cool videos, but after reading these papers I’ve actually realized that researchers have been thinking about 3D interfaces for a really long time.

There’s quite a bit of research already out there about 3D interfaces. There are a lot of existing interaction techniques exploring navigation, menu selection, and object manipulation using 3D interfaces. What especially surprised me is that the bulk of this research was done over 15 years ago, when I was barely old enough to ride a bike. The chart above shows the number of publications per year relating to 3D interaction techniques ((Bowman, D., Frohlich, B., Kitamura, Y., & Stuerzlinger, W. (2006). New Directions in 3D User Interfaces, I recommend this and the book 3D User Interfaces for a good overview of existing work). I was very surprised to find that the research has peaked in 1995, and has seemed to quiet down since then.

Judging by the problems plaguing 3D interfaces such as Kinect and Wii (and their limitations), there’s clearly a lot more research to be done in the area of making 3D interfaces usable. For example, most of the papers presenting new 3D interaction techniques in the 90s performed studies that evaluated a single gesture (or small gesture set) to solve one specific task rather than an entire gesture language to execute a collection of tasks. Perhaps now that 3D interfaces are emerging in consumer products, we will see a resurgence of research that focuses on the development of entire gesture languages that enable a rich set of actions, are robust, and easy to learn. I just hope future researchers realize that there’s a huge mountain of work to build upon, we really are standing on the shoulders of giants here.

Drastically Improved Version of Headshot Released!

Photo by Chloe Fan

Headshot is an application that helps you take pictures of yourself by telling you how to move your camera until your head is in the right spot. This was not an easy task. Writing the face detection was the easy part. Much more challenging was to get the user interface correct. How do you tell people how to move their phones? How often do you tell them? How do you teach people to use the app? The first version of headshot was a good start and got people excited, but it still needed a lot of work.

Over the last few months I’ve been polishing headshot, getting feedback from users and trying to develop the right audio prompts and timing to help you get that perfect shot. Here is a summary of all of the improvements for version 3 of headshot:

  • Added multiple person mode Now you can get the perfect shot with two or more people! In multiple person mode Headshot gives instructions by taking the average location of all faces in the image.
  • Auto snapshot when perfect physically snapping a photo can cause blurry images. Now headshot will automatically take a photo when your head is in the right place so all you need to do is smile!
  • Greatly improved audio feedback Headshot now has a bit more personality: It tells you when it can’t see you, and also immediately tells you once your head is in the right place.
  • Fixed bug that caused app to crash on international phones. This bug caused many international users to be unhappy. It should be fixed now!
  • New logo! Thanks to my friend Chloe Fan for making the avatar used in this logo. Update: The new logo hasn’t propogated to the Marketplace yet but it should be up soon.
Excited? Then please update your app, or download headshot by following the link below. If you like it, please review the app, and send all feedback to


The Story of Headshot

I’m releasing an improved version of headshot today (see this post) and in light of this I wanted to tell everybody how Headshot came to be, and what I’ve learned in developing the app.

I came up with the idea for Headshot somehwere in between my cubicle and the microkitchen at Microsoft Research. The idea was to write an application that helped people take pictures of themselves by using face detection to help them adjust their camera until their head was in the right place. I half expected the idea to work, and thought the idea was novel enough to get me into the finals for a Microsoft Intern mobile app contest that summer. Several of my closest friends told me the app was completely useless because of front-facing cameras, but I continued on, spurred on by faith and a desire to complete what I had started. The end result was a decent app and accompanying video (below) which surprisingly enough won me a brief glimpse of the limelight and a trip to Hawaii.

My contest win and a Computational Photography class spurred me to further develop the app from a prototype into a product. I released Headshot (a paid version and an ad-supported free version) on the marketplace in early 2012.

The app tanked. Twice. It got decent reviews in U.S. markets but was doing very poorly internationally, and nobody was buying a full version. It makes about 9 cents a day right now. Not something I’d consider a success given the novelty of the idea. Why is it doing so badly?

Is it because people don’t find it useful? I don’t think so. My friend told me that a necessary but not sufficient condition for having a successful app has to do with how much time to spent perfecting it, getting the polish just right. That’s what I’ve tried to do this third time around: I’ve spent quite a lot of time perfecting the app, getting feedback from lots of different users about what works and what doesn’t, testing the app on different devices, and trying my best to release a perfect product.

I don’t know if this story has a happy ending, we will see how well the app does. I do know that I created something I’m proud of, and that I’ve learned many lessons from the different phases of the app, here they are, in chronological order.

  1. Finish what you start. I never would have won the contest if I had listened to my friends who told me I had a bad idea.
  2. Sometimes offshoots of your project are more rewarding than the project itself. I’m very glad I wrote the face detection library, to go with this project, in some ways I’m more proud of it than headshot itself.
  3. Always make a free version of your app.
  4. It is essential to give your app to many people (at least ten) and see how they use it. Have them use all versions (free, paid, trial). Also, make sure you actually listen to their suggestions.
  5. Spend 3 times more time on something than you think you should. This is at least how long it takes to get an app polished. Though I admit I’ve yet to see whether this actually makes a difference.

That’s my story. I hope you enjoyed it. If you could download and review headshot, I’d really appreciate it:

Programatically Setting Image Source in Metro Style Apps with WPF

This post is for people writing “Metro Style Apps”, or apps built for Windows 8 who are trying to set the source of an image within their WPF project. It should be easy to do this but it is surprisingly tricky and took me 1.5 hours to figure out. Here’s the code:

// Usage
myImage.Source = ImageFromRelativePath(this, "relative_path_to_file_make_sure_build_set_to_content");

public static BitmapImage ImageFromRelativePath(FrameworkElement parent, string path)
      var uri = new Uri(parent.BaseUri, path);
      BitmapImage result = new BitmapImage();
      result.UriSource = uri;
      return result;

And here’s why it’s such a pain: WinRT applications need the full path to an image, they do not accept relative paths. The full path is confusing, but you can get at it if you’re in a class that extends FrameworkElement (basically any UI element) via the BaseUri property. Totally not obvious and not easy to discover!

3 Pro Tips for Surviving Red Eye Flights

I have found myself on 5 or 6 too many red eye flights during my cross country excursions between Pittsburgh and Seattle over the last year or so. Red eyes are great, if you can manage to get enough sleep on the flight and face the next day feeling more or less rested. I have successfully done this 1 out of 6 times. The last time was today. Sure, I probably just got lucky this time, but I do know that I had a couple of tricks that I’ve picked up which I’ve noticed make me feel much better, and which I think are worth sharing. Here are three things you can do to make your red eye trips easier. Feel free to add more tips in the comments:

  1. Bring an eye mask and neck pillow, and take off your shoes. This is the only way to go on a red eye. These add so much to your comfort. I try to get a window seat as often as possible so I can lean against the window. Prop your pillow against the window for maximal comfort.
  2. Brush your teeth and drink some Emergen-C the next morning. I always bring an (empty) water bottle with me to fill with water + emergen-c. Drinking the emergen-c and then brushing my teeth really feels amazing.
  3. Keep napping until the plane stops. Unless you’re in first class, it takes about 5 – 15 minutes to actually get up once the plane has stopped. Don’t waste precious sleep time by waking up early. You’ll have plenty of time.

Face Detection for Windows Phone Gets a Face Lift

It’s been almost four months since I released my windows phone face detection library and I’m surprised by two things:

  1. Microsoft still hasn’t released a face detection library for windows phone
  2. People actually downloaded my library! I’ve gotten almost 270 downloads in 4 months which isn’t stellar but it’s better than I expected.

I’ve released a new version of my face detection library, you can get it at There are two big changes there:

  1. Major fix so that library works in other countries. I have never had to worry about parsing strings in different languages but apparently ignoring this caused my library to totally not work in other countries (this also caused Headshot to not work at all in other countries which is too bad and explains my poor rating there.).
  2. User control for managing camera. I find interfacing with the camera annoying, so I created a user control that you can use to show you a preview of what the camera sees and also lets you programmatically take photos and save them to the camera roll. It’s a useful little gem in the library.

I was really surprised by how long it took me to debug the localization problem. I was even more surprised by how I solved it. I posted a request on twitter for help with my problem, not at all expecting to get a reply and lo and behold, I got a reply! I was pleasantly surprised by the competence of my social network. I guess it helps having both Russian hackers like Vadim, Alexei and Misha, and having amazing researchers like Andy, Ken and Scott all in my social circles. Being able to ask these people anything makes me so much smarter, I always forget how useful just asking people for help is.

So, moral of the story: don’t be afraid to ask questions!

In other news, my blog name is actually relevant now that I do actually climb. Beta is super helpful. I was able to get a v4 that I think would have taken me weeks in just a day because somebody showed me how to do it. Like in climbing, so in coding I guess.


So, What Am I Doing at CMU?

This post is for all my friends and acquiantances that might be wondering what on earth I’m doing at Carnegie Mellon for my PhD. The truth is, I’m doing a variety of things here (I always a variety of side projects to keep me motivated and usually you hear about them in some form or another), however my main research is about probabilistic input. DISCLAIMER: This is NOT a thesis proposal, and there is a chance I might do something entirely different for my PhD thesis, however right now probabilistic input seems like the most likely candidate.

what is probabilistic input?

In a nutshell, the goal of my work is to make user interfaces account for more information when deciding what it is you’re trying to do. I am designing, building and evaluating a new method for modeling and dispatching input that treats user input as uncertain. Modern input systems always assume input is certain, that is it occured exactly as the sensors saw it. When a developer handles an event (say, a mouse event), that event has one x and one y coordinate. This works well for keyboards and mice, but less well for touch, and even more poorly for free-space interactions such as those enabled by the Kinect. After all, your finger is not a point! The stuff I’m working on will allow our input systems to be far more intelligent about interpreting user actions, especially for new input techniques such as touch, voice, and freespace interactions enabled by the kinect. In addition to enabling computers to better understand users, I’m interested in evaluating how we can use this probabilistic approach to design feedback that allows users to better understand how computers are interpreting their actions. For example, what’s the best way for a computer to tell you that it is not sure whether you’re doing a horizontal swipe, or a panning gesture for the kinect? If you think about it, a lot of the interactions you do can be interpreted multiple ways. The challenge of how to communicate this to users to that you understand stuff is ambiguous without being confused or working to hard is a problem I’m trying to solve. Finally, I would like to evaluate how easily developers can adopt this probabilistic approach into real applications, as the ultimate goal of this work is to eventually be adapted into all input handling systems.

what have I done so far?

Most of my work so far has been in designing (and validating through implementation) an architecture for actually dispatching uncertain input. In other words, assume that mouse events now aren’t at a location, but rather have a probability distribution over possible locations. I designed a system that figures out which buttons these new mouse events should go to. This system was published in UIST 2010, you can see the paper here. I then published a refinement of this system (with a few extra bits) that made it much easier for developers to write user controls (buttons, sliders, etc.) for my system. This was published in UIST 2011, you can see the paper here.

what is left?

Right now I’m working on designing better feedback techniques when input is uncertain. After that, I’m going to try to tackle mediation. What’s mediation? It’s basically what shoudl happen when you do something (like a gesture) and the computer can’t decide between two things. So, it asks you what you wanted to do. If it just asked you and had you pick from a list, that would feel unnatural (because it’s a break in your workflow). So, I’m trying to see if there are better ways to mediate between alternate actions. The last piece of my thesis is perhaps the most important and most difficult. It involves evaluating my work on real developers. This is still an unsolved and mostly unexplored area for me, though I know I should be working on it.

what is the best possible outcome for my thesis?

I would be thrilled if at some point in my life I saw mainstream input systems such as those in Microsoft and Apple products turning probabilistic, and if those systems used some of the ideas outlined in previous papers, or papers to come. Given the popularity of natural user interfaces, I think this is a very real possibility, which is quite exciting.