I'm just going to add, unless you have tried to port Android to another platform, you have NO IDEA HOW MUCH PAIN AND EFFORT IS INVOLVED.
I'm doing work on Android OS at the moment, and it's HORRIBLE.
Had to get that off my chest.
Principal Software Engineer at Raspberry Pi (Trading) Ltd.
Contrary to popular belief, humorous signatures are allowed. Here's an example...
"My grief counseller just died, luckily, he was so good, I didn't care."