Earlier quoted context omitted.
Microsoft had an Android compatability layer in WM10 betas, as well as an iOS layer. They didn't launch either, afaik, running the apps without platform services isn't great, so then it's a push towards developers --- port your app to WM10 much easier... But there's still work, and IMHO, the user share on WM10 wasn't compelling enough for new developers to do the work. https://seekingalpha.com/article/3447036-microso…
They did actually release phones running Android with a Metro skin: https://en.m.wikipedia.org/wiki/Nokia_X_family https://m.gsmarena.com/nokia_x-6067.php
Forked Android with a Metro launcher and maybe they skinned the rest of the UI. I think I remember WhatsApp doing work to support them while I was there (anything Nokia made and didn't cancel before launching would have and sell enough units to matter), but I don't remember how hard we had to work; I'm guessing it didn't have google play services, but I don't remember if it had its own push services or if it just used long connections. I think maps/locations was weird because Nokia didn't hook the Google apis, so that was a bit tricky. I don't know if it could use the website distributed apk or if Nokia had an appstore, etc.