I'm getting close to completing my current Android game and I was thinking of adding achievements to it, and gamejolt came to mind. However, I think I am the only person who has ever posted an android app here...and it was just a test of the achievements system :C
I think adding support for android apps would bring in a wave of new users and developers. by 'support' I mean something simple like auto-generated QR codes for downloads (like the one in the screenshot for my app http://gamejolt.com/freeware/games/android-trophy/screenshots/view/5736/)
If a lot of people start developing apps and use this achievement system it could become a popular platform for more than just achievements(eg highscores, game data cloud, etc). Or a GameJolt market app with a list of indie apps from gamejolt
Also, I'm not sure how this would work out but maybe an in-app advertisements as a complement to the revenue system....nah, probably not, but its something to think about :P
So...yeah, what do you have to lose? :)