How can I unsubscribe from iOS pre-releases? I added the pre-release profile to my primary iPhone so that I could use Night Shift. I considered the stability risk a fair trade off, because f.lux significantly improves my life, and I wanted that benefit on my iPhone as well. iOS 9.3 is out now, and I'm currently on a stable version. I don't need any pre-release features anymore but, I still get prompted to update to new beta versions. To prevent this, I've removed the profile in Settings.app, but the update prompts continue to appear. How can I re-enter the "stable releases only" upgrade path?
Usually, the procedure for doing this is to delete the profile in the Settings app, then restart the phone. If you didn't reboot then it's possible that it still thinks you have the profile.

Make sure you have not accidentally allowed it to update to a beta version (for example 9.3.1) as it's possible that if you are currently running a beta version then you might still get the later betas.