It's a brilliant idea, and once you get it going it's easy to use, like all the Tone Print series.
The first one I was sent had problems - wouldn't connect to Bluetooth, couldn't load some artist presets, and whilst carefully following the firmware updater instructions, after 12 attempts it just bricked.
The replacement however works fine and is outrageously handy on a small board.
For me I'd say the "instructions" let it down. It isn't made clear that the Bluetooth is a bit special - the pedal won't show up on any devices list on iPhone or Mac no matter how much you mash the button, but will only connect to the app FROM the app. Once you're in, it's plain sailing though.
Also the pedal's foot switch function is tricky to get at first, you have to mess a bit to get it how you want. Some of these finer points could have been mentioned. If they were, then I couldn't find them.
You need the latest firmware to use some of the effects, but given my experience, I don't fancy that again.
All in all, after a shaky start, I'm well pleased with the sound, ease of use, price and concept. If they can sharpen up the rest it'll be perfect.
Like all tech products, if you're prepared to put in the work, you'll get a great pedal. Thumbs up.