You can make them in adobe photoshop, yea.
Open up a Photoshop document and begin with an image. Let's say it's a stickman. Make a new layer (Layer: new Layer) with the next cell of animation, like his arm moving up a bit. Next layer is the next cell. So now you have about 20 layers that if you scrolled through them make an animation.
Now, you go up to File: Edit in Imageready.
Usually what I do is I have all of the layers turned off except for the first frame. Not so much off, as invisible. Go to Window: Animation to turn on the bar so you can control what becomes a frame.
At this point, I go down, frame by frame and as you make them visible you click on the " duplicate layer" button on the animation bar. It's next to the trash can icon. You can control how many seconds a frame in shown under their individual frames. Then you can Save Optimized as whatever. I'd suggest trying this out first, because I use a Mac and I may have a different version of Photoshop and Imageready than you may have.