You are really late.
In case you haven't heard of it yet, the people who made the Ubuntu Desktop Operating System recently announced their new mobile OS, known as Ubuntu phone.
You can find more details on their web-page, here: Ubuntu for phones | Ubuntu
A video by Ubuntu on the phone:
(start from that point just for the phone, you'll know when it ends. developer stuff afterwards).
You are really late.
Ubuntu phone sucks right now. My friend installed it, and most of the stuff isn't even there, it's just placeholders for when they finish it
It sucks... I had it and had to go back to 4.2 JellyBean. It doesn't let you install stuff and is very limited.
It's still in pre-alpha development stages. The only reason they allow people to currently use it is for testing purposes.
This looks interesting and I'll try it when it's nearing beta, I'm not much for bleeding-edge releases.