Great, could be perfect if:

This app is amazing, its easy to show proof of concept to the band by dubbing harmonies and assorted instruments.etc and its pretty fast to get up and running.

Bugs:
The input bugs out sometimes and feeds back through the speaker- it requires a full restart.
I also have not been able to get the fx to work.

Features:
It would be nice if it went back to the song creation menu after opening the app because it easy to record over an old track thinking its a new session.

Would love if waveform editing was implemented on an individual and group track level so I could make simple edits to cut out excess playing, talking.etc

And it would be cool if you could import material from voice memos. I dont know if this is possible: due to system access rights.

vogues.m about FourTrack, v6.0