Why do certain apps open upside down?

Hey, John!

Thanks for visiting the Apple Support Communities. I understand that some apps are opening upside down on your iPhone. I'm happy to help!

Your iPhone has an internal accelerometer that gauges it's physical location in the world. This accelerometer tries to determine the position the iPhone is being held in and opens apps accordingly. If your phone is being held at too much of an angle in one direction, the accelerometer may interpret that as the phone being held in a different orientation all together. Therefore the first thing I'd suggest is making sure your phone is being held mostly upright when opening apps. Even having it flat on a surface (like a desk or table) may cause the accelerometer to open in an incorrect orientation.

If the issue happens no matter how you're holding (or resting) the phone, I'd next check to see if orientation lock is enabled: Rotate the screen on your iPhone or iPod touch - Apple Support.

And restarting the phone is also another recommendation I have: Restart your iPhone - Apple Support.

Should you still have trouble after that, don't hesitate to respond back.

Have a great weekend!