[Fizaaa]

I've been wondering what this was for a really long time now...
Theres a little dot on my "D" button on my phone. It lights up too, lol. I don't know why it's there and what it's purpose is.

I would show a picture but i need 10 posts...

[Pi Guy 3.14]

I'm pretty sure that is indicator for your finger placement used for typing.

Its the same as the F & J on your keyboard. They're called the 'home keys'.