In this video Leszek Lesner tells you how to enable the Low Power Mode (LPM) / Glance screen on SailfishOS which offers you an always on display solution.
You need to have mce-tools installed. Then you can execute the following commands as devel-su (root) user.
mcetool --set-low-power-mode=enabled mcetool --set-ps-on-demand=disabled mcetool --set-blank-from-lpm-on-timeout=35 mcetool --set-lpmui-triggering=from-pocket,hover-over
A premium mobile Linux operating system from Jolla. Sailfish OS is a continuation of legendary MeeGo (of Nokia fame).
Sailfish OS is an alternative for mainstream offerings for a stable and secure daily driver in smartphones. Many Sony Xperia devices +much more supported now!
SailfishOS or SOS for short.