I was recently commissioned to wireframe, prototype and GUI design an Android app. While I am highly experienced with UI/UX/GUI design for mobile iOS apps, I have very limited experience designing for Android, and I don't even own an Android-running device to perform tests.
1) Given my solid experience and know-how of designing for iOS, I am looking for a good walk-through covering all the critical points (and differences from iOS) one needs to know before designing for Android. In particular, delivery formats, size constraints, UI patterns, etc.
2) Given that I don't own an Android device, would it make sense to use online emulators or other software to run and test the app I'm designing for? If so, which emulators / online services would you recommend?