What challenges did you encounter during the development process, and how did you overcome them?

Developing the app for Android you should already know how android OS operates on the inside. But I started from ground zero and it was very tricky to grasp how all the intrinsics work so that resulting application can be regarded as "reliable". I'd also say that overcoming such obstacles is not a one-time action but rather the long and mostly unsure process of eliminating errors.