I must have been lucky, but Caffeine works for me on several different devices and it works well. I run it on Alcatel Pixi4, Alcatel POP4, Google Nexus 4, Lenovo tab7 and an ancient Kindle. I use BridgePal launcher so when I turn the device on, after half a minute I get CONNECTED... message and the Caffeine icon on the status bar on top of the screen. Screen is dimmed as expected until I tap it.
Here is how I set it up::
- On the Settings under Display set Sleep to the desired timeout – I suggest 1 minute
- Start Caffeine, then
1. Set Caffeine to On
2. Under Brightness – set to Dim after system display timeout (as above)
3. Untick Deactivate when screen turns off
4. Auto activate on USB – unticked
5. Click on Activate caffeine for applications and tick BridgePal (and Bridge Solver if installed and in my case Nova launcher if my specially configured Kindle)
6. At this point a screen message pops up telling you to turn on Caffeine accessibility service etc. There is an option TURN ON in red next to it. Click on this. scroll down to Caffeine and tap on Off – this will turn the accessibility to On
7 Tick Enable caffeine at boot
8. Tick Activate at boot