What tools/application/webs do they use to make nice description photos?
e.g https://play.google.com/store/apps/details?id=com.instamag.activity
The demo pictures are very nice, any PS templates I can use?
If you want screenshots of your phone running your iOS app, I used this with excellent success: https://itunes.apple.com/us/app/screenshot-maker-pro/id673545271?mt=8
For android, you could just use this: http://developer.android.com/distribute/tools/promote/device-art.html