Regarding the android pi installation I'm currently downloading android 6 from here
https://github.com/Android-RPi3/android_releases_rpi3/releases

I noticed that theres also an android 7 build but I don't have enough SD cards. if someone else wants to have a go at getting android 7 running on raspberry pi it needs to be built from source:
https://github.com/peyo-hd/device_brcm_rpi3/tree/nougat

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Kind Regards
Rowan Schischka