Problems I'm having as well as family and friends only after iOS 9.1 upgrade on a variety of iPhones from 4s to 6's;
Alert tones for text/iMessage stop working almost daily (reboot fixes it)
Apples Podcast app crashes
Lock screen timer doesn't work past 2 minute setting. (Set it for 4 mins and it locks phone after 2 mins)
Random reboots (especially when an app has permission to keep the phone live and not lock the phone).
The list goes on and on..... Yet none of these problems existed in iOS 8.
None of the iPhones are JailBroken except mine, yet we all have the same problems.
At my friends work, at the short daily morning meetings before the store opens, they all power down and power up their iPhones now as a daily requirement.
Maybe calling iOS 9 garbage is harsh, but when we all never gave a seconds thought about our iPhones working properly before and never had to reboot for months, now we're constantly checking the phone for missed messages and making sure it's still powered on.
We all upgraded our iPhones with the latest iTunes software. Also no one has complained about their iPads or Mini's, only iPhones.
Thanks for letting me vent....