One extremely frustrating facet of designing an app for the Android platform is the plethora of devices with varying screen sizes out there. Coming from a web background, where you pick a minimum screen resolution and get going, it's a rude shock. Android's own guide on supporting multiple screens recommends having four (!) versions of bitmap resources (pictures).
I did a quick survey on Flipkart for the screen sizes & resolutions of all Android phones under Rs 18,000, which I'm assuming would be the top sellers in India. Here's the data (the first column is the screen resolution in pixels, the second column is the diagonal length of the screen in inches, and the third column is the number of handsets available in that particular combination):
So, while designing for Android, you have the mental overhead of thinking about more than 12 screen size & resolution combinations. That's right -- more than twelve. Contrast that with iPhone, where it's just two, I think -- one for normal displays and one for retina displays. Contrast that with the web, where, till some time back, you had to basically pick between designing for a minimum of 800x600 or 1024x768.
Based on the screen classification proposed by Android, even if this number can be brought do half, that would leave us with more than 6 possible outcomes! I haven't even started looking at supporting multiple API versions (2.2, 2.3, 3.0, 4.0, etc.) and multiple device capabilities (scroll wheel, D-pad, etc. etc.) I'm afraid I'll give-up even before I reach that point!
Is there any report out there which segments: (a) the amount spent on the Android market & (b) the in-app advertising revenue, by the handset capability / screen size / etc? I'm sure app developers would be willing to pay for it, to save themselves the time spent on handsets generating a few hundred rupees, at best.