Give it a try - I think you'll like it!
I've had this app installed for quite some time, but as I don't play many games, I hadn't ever got around to playing it for more than a couple of minutes. Well, I've finished it now, and I'm impressed.
To be clear, I'm pretty sure that I bought this due to my friends and I being long-term players of their EXCELLENT (and now sadly removed) Carcassonne game. THAT game was perfectly implemented, with no bugs that we ever found (I reported what I thought was a bug at one point, but they politely pointed out that I was wrong!), even after years of playing, so their attention-to-detail is exceptional.
'OBT' is no different. It's clever, detailed, and bug-free - at least in my perfectionist opinion. I thought I'd found a typo at one point - but quickly realised that was a plot device, and therefore intentional!
Obviously, no spoilers here. It's a medium-length, interesting, real-time, quirky, funny adventure. I highly recommend you put a little time into it, you won't be disappointed. It's certainly worth the current GBP 2.99 asking price for a few hours of fun. Just ignore the old, negative reviews found here!
Oh, and I played it on an iPhone, which worked perfectly. I plan to get an Apple Watch soon, and I suspect that this game would be even better on that - the Watch is probably the ideal medium for such a real-time, interactive game!
Overall, thanks and well done to TheCodingMonkeys!