I've had the cardboard version for ages, but have yet to find anyone willing to give it a go - so I caved in and bought the app shortly after the third update came out.
It's certainly playable, but the app assumes that you know the rules beforehand. There's no tutorial and very little feedback on what's happening on screen. On my first game, I tried placing a second worker on the main board - but rather than tell me that you can't do that, nothing happened. Also, the screen layout is from the PC version, so there's a lot of scrolling between the main board, player boards and ressources.