Note: author can no longer maintain this app. If you use it, please report back whether it still works.

Cryptonite brings EncFS and TrueCrypt to Android. You can browse, export and open EncFS-encrypted directories and files on your Dropbox and on your phone. On rooted phones that support FUSE (e.g. CyanogenMod) you can also mount EncFS and TrueCrypt volumes. TrueCrypt is only available as a command-line version at this time.

This app has a canary on its source page. Watch out for the phrase: „I haven’t had any backdoor requests yet“.