It might seem a trivial task, but your app should be found if people search for it on the Android Marketplace, it should be at least possible to guess what the app does if you see the name and it's bad if the name in itself is an intrusion in someone else's trademark etc.
I was planning to call my game "JustRoids" and did a quick search on that name on Google and Android Market Place: https://market.android.com/?hl=sv.
I came up with exactly zero hits, so JustRoids it is!
(If you are completely out of ideas, you might want to try "The Video Game Name Generator" at http://videogamena.me/. It will suggest names like "Confusing Handgun Maniac", "Mystical Hair Salon Wars" and "Toxic Fun - The Quickening" that are at best of limited use, but it might still give you some fresh ideas ;-) )