I'm not a Windows Phone user so I am a bit out of my element in terms of typical application design for the phone, but some sort feedback when a user is performing an action would make the app feel more responsive.
For example, when posting the picture to Facebook the application could show a spinner with the words "Posting to Facebook"
Actually there's a spinner at the bottom of the window. (That's not visible in screencast because it is a little bit small.) However it does not have words, it's just an animation.
To make the sort of app really fly it helps to make it so that the people viewing the produced images can't avoid knowing the image was produced by Colorify. For instance you could host the produced images on a Colorify site, so that people can see how it was produced (and learn more about the app). They then will be compelled to download the app and make their own images, which act as an advertisement to your app.
I agree with hammerdr above that more visual feedback to the user would be good. The part where the image is being converted to B&W would be a good place to start.
A very interesting way of highlighting parts of images. Perhaps you could extend this to blurring parts of images (to highlight the unblurred parts)? I don't use Windows Phone, but I'll be sure to check out the equivalent apps on Android.
well, here is a canvas / javascript version of something similar http://www.barbafan.de/farbzauber/w - works best on the ipad (and iphones of course) and some modern android thingies, wp7 not yet confirmed, as i do not know anyone with such a phone (would love a wp7 works/sucks confirmation if someone has a moment to spare, thx)
I'm not a Windows Phone user so I am a bit out of my element in terms of typical application design for the phone, but some sort feedback when a user is performing an action would make the app feel more responsive.
For example, when posting the picture to Facebook the application could show a spinner with the words "Posting to Facebook"