Electrum Wallet is one of the most popular and lightweight Android wallets you can find.
After downloading and installing the application, you are given a random 12-word secret combination while creating your wallet. You have to write it down and keep it aside. If one day you encounter a problem on your Android device, you can easily recover your wallet with this word combination.
Since your private key is not locked in the wallet, you can easily transfer your Bitcoins to another wallet.
The application, which also prioritizes security, asks you to specify a 6-digit PIN code that you will use for payments. If you are concerned about security, you can use the mobile application to view only your Bitcoins. In this case, the payments are made from the desktop application, and the payment functions in the mobile application are disabled.
One downside of the app is related to QR codes. The application has QR code support, but the QR codes it produces can only be read through the ZXing QR application.