FindIt
https://play.google.com/store/apps/details?id=com.findit.client.activity
FindIt is a very interesting app that can help you get organized and more productive when doing work on the go (on your Android device). In short, the app allows you to search through your Gmail, Google Drive, and Dropbox accounts. You can look for people, files, anything. It comes in really handy when you need to find a file and send it to someone, for example.
Tophatter
https://play.google.com/store/apps/details?id=com.tophatter
Tophatter is basically like eBay, only faster and more interactive. The idea of this service is to provide online auction functionality, but what sets it apart is a cool interface and the possibility for sellers and buyers to chat with each other as they bid along. This makes the whole experience much like a real world auction.