LibRCrypt is an Objective C library for complex data encryption based on Rubik's Cubes. The idea's pretty simple: If you represent data as the squares on a Rubik's Cube, you can apply transformations to the data and get back encrypted data, all of which is commutatitive. Just as a Rubik's Cube can be solved if you know all of the moves, this data can be "unwound", so to speak, if you know all of the transforms applied, but the encryption is even deeper than that. A cube can only cover (9 squares per face x 6 faces) 54 significant bits of data. Therefore, compressed data must be composed of multiple (even thousands) of Rubik's Cubes.
jGoogleCalSync is a Java application that uses the ICS file format to access and upload calendar information in GMail's Calendar. The application has been built to upload Lotus Notes calendar information. Once the Lotus Notes information is in GMail calendar, it can be synchronized via CalDAV towards an iPhone or other calDAV-enabled devices.
iDeviceBrowser is an application that makes it possible for you to view and edit files on your iDevice (which includes the iPhone, iPod Touch, iPad, and Apple TV). In conjunction with "afc2add", which is available via Cydia, it allows access to the full file structure, or else just the /private/var/mobile/Media/" directory.