HTC is tipped to add Guest Mode in the next major update for the One M9. This would let users lend their phone to someone else without having to worry about other people seeing their personal information or files.
HTC developer LlabTooFer tweet a suggestion that Guest Mode is one of the features that will be added to the One M9. It doesn’t mention the feature explicitly, but the tweet contains a picture that shows the ability to add users.
The next major update is likely to be Android 5.1 Lollipop. There’s no word as to when this update will roll out to the HTC One M9. Google has started rolling the Android update out for a number of handsets. Last month, HTC revealed that the Android 5.1 Lollipop update will start rolling out to the One (M8) in August.
This update will also add the ability to control the One M9's screen colour temperature. It’s not quite as big an addition as Guest Mode, but it’s a nice touch.