The same developer also made another app that goes without OTG USB cable but as it is called Delay effects because it has so much latency so the developer is saying that you can use it to harmonize with yourself!!!
Ahh you have to love that you can take a disadvantage and turn it around like that.
Anyway if there is someone that have tried the usbEffects app and want to tell us about it or give us some sound samples please do...
You can send your observations and/or sound files to here:
musicalandroid@yahoo.com or post in the comments.
I am curious to hear how good it is and also if it is as they say that the latency through the OTG-USB is low enough to be usable as guitar effect...
Playstore links:
usbEffects
Delay Effects Plus