There are several rather cool apps for FFOS, even though most of them are rather customized websites than true "apps". For instance, the XKCD reader is something that I really like on FFOS. There are several other nice apps, such as newsapps etc.. Nothing absolutely necessary, but still nice to have. And since it's possible on Android, why wouldn't it work on SF??
BTW: The nightly build never chrashed for me yet, thanks a lot!!