A bunch of tools, to create/edit images, to resize and convert them. There are also tools to find the "sauce" of a manga or handling GIFs.
When dealing with images, you may want
- Google's search by image
What's the sauce?
This website is supposed to help you find the sauce when someone is posting a chapter of a manga. It didn't work for me, but who knows, maybe for you, it will?
You can make GIFs using