Personally, I use GIMP for animating.
And drawing, graphics, coloring, everything.
I've been told that it's just like Photoshop (I had to be told, because I've never used Photoshop. xD), only, it's completely free to download. c:
You can set your own times between frames, too, in milliseconds.
It takes a while to learn to use, but there are tutorials e'rrywhere.
You can find it here;;
http://www.gimp.org/downloads/
Hope this helps~ c;