The Ultra Power Saving Mode on the Galaxy S5 allows the handset to last for nearly 30 hours on only 10% of charge. While Samsung disables all the apps in this mode, it still allows users to specify a few non-basic apps that they could use as well including Hangouts, Whatsapp and Internet.
However, other popular third party apps are not supported, which is a bummer. XDA member xperiaacle aims to solve this problem with the Ultra Power Saving Mode manager app for the Galaxy S5. The app allows users to customize Ultra Power Saving mode to add any app they like including a music player, Google Maps, Sygic Navigation and more.
The catch here is that the app must be read by the UPSM framework on the Galaxy S5, otherwise it won’t show up in the list. It also does not remove the six apps limit present under the Ultra Power Saving Mode. If you have not already guessed it, using the app requires root access. With Geohot’s Towel Root making it a breeze to gain root access on any Galaxy device without voiding its warranty, this requirement should not really be much of an issue for S5 owners now. You can purchase the latest version of UPSM manager from the Play Store or download a slightly outdated version for free from this XDA thread.