In the web there are many programs for the creation of files ... in my case, I went for the more complex side because I did not have much experience, so ... that is a program called Easy GIF Animator ... but that I could use only that time because you have the program to be able to follow it and I do not have that money. So I'm learning to do the .gif in photoshop or sai or other drawing programs ... but do not worry that even with power point you can do them :)