LockPic helps you protect private information in images in a secure manner. This is achieved distorting regions in them, e.g. faces, so that people appearing in them cannot be recognized. This way, photographs can be shared in social networks respecting privacy. There are other applications out there that can help acomplisingh the same goal, e.g. ObscuraCam, but with LockPic the process is reversible.
The owner of the image can grant decryption rights to any part of it to other people, and a cloud-based permission management system allows users to recover the information from anywhere.
Using the app for encryption is very easy:
Both the android application and the permision server are licenced under GPL v3 and their source code can be download from GitHub
The LockPic application is also avaiable in the Android Market.