shouldn't be any issue with impedance into the front of the amp. it does suggest it's geared towards apple devices, and gives an ideal volume setting. i haven't tried it yet, but i will. i am a bit sceptical too. obviously, it won't sound exactly like you playing through your amp. but it should give you a much better idea of how the effect will sound through your own gear than a youtube video.
it's pretty cool that you can take a demo of a pedal and set your amp however you want; clean, just breaking up, overdriven. it's a fabulous idea, and i hope it does work well