This app creates transparent graph on top of everything, this graph can display CPU GPU or RAM information.

Warning: Android Oreo (8) brought security changes so at best CPU utilization does not work, maybe more

App is configured for several phones, if something doesn't work file paths from where app reads data can be changed on Sensor configuration page.

Graph is fully customisable, you can resize, set number of CPUs to be displayed in a row, display CPU or GPU utilization, frequency or temperature.

Image transparency is customizable and you can set monitor update interval.

Tapping on graph opens configuration page, where you can enable or disable all CPU or GPU options in real time