Micopi
NOTE: As of September 2016, this project moved to a private repository. Further changes are not merged to the GitHub repo.
Micopi allows you to assign an image to every person in your telephone's contact list. So if you do not happen to have a (decent) photo of them, you can use the app to simply generate one. Micopi does not use a random number generator to create these images. It exclusively uses contact data such as the name, the telephone number or the e-mail address and turns these into geometric figures and colours. This way, all of your contacts have their unique image. This app has been thoroughly tested but we recommend making a backup of your most precious contact pictures, just in case.
Micopi Free in the Google PlayStore
All files use the Apache License Version 2.0 (see http://www.apache.org/licenses/LICENSE-2.0.txt). The app is currently in a stable release state and available for free for all Android devices running version 2.0.1 or higher (API 6). An iOS version is planned.
As long as you give me credit, feel free to modify my code or use my algorithms for your needs.