(Based on GIMP tutorial: Simple Animations)

1. Import JPEG images by dragging files
2. Insert Text and Copyright notice - Please, try to use CC Attribution-Noncommercial-Share Alike 3.0 Unported
3. Export As a GIF image
4. Select GIF option As animation and Loop forever
5. Define Delay between frames, around 1000 ms will do it, but change as wanted
6. Select Use delay entered above for all frames if you do not want to specify different delay for some frames
7. To specify different delay for some frames, go back to Edit Frame Attributes

Using GIMP as an animation package