Doesn't Work In Ultra Power Saving Mode (On Samsung Devices).

[lejshi3]

Not actually sure how this can be implemented, but newer Samsung phones have OLED displays. Combined with Ultra Power Saving Mode and a Dark Theme, This app could last a week on one charge.

[joleeee]

It seems the list of apps you can add is curated by Samsung so that makes this hard. You can always root your phone and add it manually if you really want it. It seems like the application (UPSM Manager) is abondoned and it's last update was for the S5, which is a bummer since I'm on the S6, but I'll look around and come back here if I figure anything out.