Sure, Facebook is a social network used commonly for ranting, raving and sharing vacation photos. Facebook is also a platform. Web developers can build applications within the Facebook environment or that use Facebook data within external applications or websites. Facebook applications can be found and managed within the "Apps" area.
Facebook applications can be highly useful for engaging with new audiences and building brand visibility indirectly. If you build really fun or useful applications, you will have another reason to attract users into your brand's ecosystem. Successful applications can build audiences quickly. As with any brand touchpoint, building a Facebook application means you will have one more asset to promote. Success will not come automatically.
Examples of Facebook applications
- Photo galleries related to your brand's activities, event or the industry as a whole
- Games
- Puzzles
- Trivia quizzes that have a fun competitive quality and viral sharing tools
- Sharing New year's resolutions
- Personal goal sharing apps - share your personal commitment to achieve some goal
- Voting app with ability to promote the results
- Goodie Downloads
- eBook Download
- Photo Voting
- Video Gallery
- Newsletter or blog integration
- User or customer rewards
- Inspirational or humorous content served on a daily basis
SOURCE: https://developers.facebook.com/docs/guides/policy/examples_and_explanations/