Doesnt work on iPhones

Upgraded Night Sky Pro on 3 devices. iPad mini, iPhone 5 and iPhone 6s. The iPad mini with iOS 9.3.4 works fine.
The two iPhones with iOS 10.1.1 do not work. The horizon does not calibrate to the compass at all. Wrote to iCandi Apps three weeks ago and have yet to receive a response.
Dont loose your Pro because it works and NS4 doesnt on iPhones.

Gronk49 about Night Sky, v4.1.1