Looking For Free Multi-Track Recording Software Best For Recording Vocals

Hi,

I am looking for free multi-track audio recording software for iOS that is easy to use and optimal for recording vocals. I already tried GarageBand and Hocusai 2, but both of them weren't that easy to use and I couldn't get to the audio recorder interface in GarageBand. If possible, I would like recommendations for such software that has the capability to add voice effects, (auto-tune, muffling etc.) I own an iPad Air 2.

Thanks in advance!

Sincerely,
Maddy