Ever tried sharing a Bluetooth speaker with someone? Your iPhone connects to it just fine, and you're able to throw a killer dance party.
But then comes time to disconnect your iPhone from it, so your friend can take over DJ duties.
And that's when the problems start. In order to disconnect your iPhone from the speaker (or any other Bluetooth device for that matter), you have to either temporarily disable Bluetooth on your iOS device, or opt for the nuclear option of "Forget this device" in Bluetooth settings.
Neither solution is all that practical, but they work.
With iOS 9, however, you now have a new option to actually disconnect from the device without jumping through hoops.
The next time you encounter a situation where you want to disconnect from a Bluetooth device, launch the iOS Settings app and select Bluetooth from the list.
Tap on 'i' next the device name, then tap on Disconnect.
Every iOS release offers small and big tweaks to the OS, and only a few deserve the label of finally -- but as someone who dealt with this issue all the time, I think it's appropriate.