I've managed to upload the source to build Android for the NanoPC T3 Plus.

It supports the SIMCOM SIM7600E/A modem for LTE support and also landscape mode on the 4.3" and 7.0" LCD's.

The modem is connected via USB interface and on my custom boards I used the PCI Express version so I could offer the system with or without the modem with a simple plug in if needed.

https://gitlab.com/davemclaughlin/androidnanopct3

I've removed a lot of the demo software and included a decent file manager.

Feel free to have a play and please give me any feedback on how this works for you.

The only issue I have is with the boot animation not showing correctly on initial boot but after a few seconds it does sort itself out.

PS. This is my first time pushing a large project to GITLAB and I seem to have missed the setting to not include the backup files from GEDIT. :(