Images
Gimp (photo manipulation - need to download)
Marqueed (markup and discuss images online)
Picture to People (online Photo editing)
Pho.to (add animation and effects to photos)
PhotoFunia (adapt your photos using online tools)
Remove.BG (remove the background from an image)
ThingLink (tag an image with web content)
PicMonkey (edit your photo, apply filters, add text, etc.)
Tutorials