I thought it was the battery on my iPhone 5s but also tried it on my iPhone 6. Since the last update randomly my phone will reboot and get in a reboot loop when the battery is about 35%. I thought it was my battery dropping out of tolerance so got an iPhone 6. This is doing the same thing. I concluded it was the jami app as when I managed to remove it the rebooting stopped.

I tried total wipe of the phone and did not do a restore (incase it was a bad setting) and the phone ran fine for over an hour. As soon as I downloaded from the app store the reboot issue started.

Have had to come to android to use the app