Here is what I did to get it working on CM12.1:
- Install latest Quick Support app from Play Store.
- Open the app and let it try to install the addon (It will probably fail).
- Find the downloaded addon (usually /sdcard/Download) and then copy it to /system/app. Do not modify the apk else Quick Support may not give you the option to remote control.
- Reboot phone and run Quick Support. It shouldn't ask to install the addon anymore and also make sure it gets granted root access when you try connecting to it.
- If Quick Support is working correctly then you may want to install Teamviewer Host as well for unattended remote control.
If it still doesn't work you should try looking in the Quick Support event logs and also upload them here.
Works great! (well, its a little delayed, but it works)