[1n9i9c7om]

You could also check out ShareX, best screenshot tool I ever used. You can either chose out of some different image hosts or enter your own.
It also allows you to add effects to your images or to record gifs. :3

[Aura]

There's ShareX that'll do the job :

http://getsharex.com/

But it's only for Windows I think.

[Orianthi]

I use lighshot fast upload and hosted on imgur.

[Jaex]

ShareX supports both FTP and custom uploader. With custom uploader you can use your own file hosting services.