Sprint customers who've picked up HTC's swanky new One M8 will soon be enjoying a new feature, as a fresh update brings the flagship's 'extreme power saving mode' to bear.
The update is number 1.54.651.8, and adds the missing mode, which conserves CPU usage, cranks down the screen brightness, turns off vibration, shuts down the phone's data connection when the screen is off, and turns off the pedometer.
As if that wasn't enough, only essential apps can be used in the power-saving mode. These are the phone, messages, email, calendar and calculator. Nobody should ever have to go without a calculator, no matter how low their power-levels sink.
The new feature isn't mentioned in the notes for the new update, but was spied by forum members on Android Central and XDA-developers. I've had confirmation from Sprint that the HTC One M8 has the extreme power saving mode, which it didn't at the time of launch.
The juice-sipping extra could stretch your phone's last five percent of battery to an additional 15 hours. It was added late in the One M8's development, which is why it wasn't available at launch in the US, with carrier's busy conducting their own testing. The feature is already available on international models -- an HTC One M8 from the UK was used to take the screenshots of above.
The One M8 isn't the only phone with a last-ditch battery-saving trick. The Samsung Galaxy S5 has a similar 'Ultra power-saving' mode that also turns your phone's interface monochrome.
Have you got the update yet? What do you think of the new mode? Let me know in the comments.