I use photoshop for small animated pixelart gifs, here is how I do it (I use it
First open the time line thing
If you don't have it open go to window> timeline
Then select create an frame animation (I think that's the way it's traduced but I have no idea) it should look like this
Now you can create new frames with the flipnote icon (the one in the center)
You can also adjust the time
Hope it helps you!