I wrote a couple of simple plugins and thought about sharing them with the rest of the community:
https://github.com/MissAllSunday/F3plugins
The first one is a light gravatar plugin, it allows your to build a gravatar url out of an email in an easy way. Can set global options via a $f3 hive var or on a per call basis.
The other one is a form generator. It allows you to build automatic forms via the less code possible while still maintaining some kind of control over your fields. The plugin comes with a form.html template which is used to display the built forms, its just a matter of including the template wherever you want it to appear.
The plugins are still pretty new and I am building them at the same time as I'm using them :P so they still lack a few features, specially the form generator one. Tests and proper documentation is also on my todo list.
I'm still fairly new to Fat Free so any suggestions or code improvements are, of course, welcome.