Hi,
Really like the look of this app, a great idea! Did not realise until recently it was even possible to have these automatic checkins on an iPhone, and I think this sort of data will add a lot to the measuring and analysis QSers can do. Outside of activity trackers like Fitbit, I’m finding little truly passive data collection an amateur like me can do, and this is a proper step forward to me (without investing a lot of research/cash??).
My main feedback would be to make it possible to get the data out of the system and combine it with data from other apps/devices. I saw on Twitter you already suggested a CSV, which would be a great start. If possible it would also be great to have it use some API to integrate into analysis portals like TicTrac or Zenobase or whatever people like to use to cross reference data, for those people who do not like to spend too much time in Excel 
For me, at a very simple level, I travel quite a lot to hotels and like to track where I sleep each night and its effect on my sleep, subsequent mood etc. Right now I do it manually (annoying, and I can forget) - but I can definitely see that this app could automatically feed in my precise location of sleep and let me correlate against sleep quality, awakenings, mood etc. And that’s just the very start!
One question I had - on the “out and about” - should that be the time I spend walking? I went on a 1-2 km walk and noticed that the timer stayed on 0 as though I had not left home. Do I misunderstand what that section is for?
Either way, a great idea thanks, and could enable some really fascinating analysis for consumers with such a low outlay (if they have the right phone!).