I needed a tool to crop images, screenshots usually. Linux has the Gimp image editing program but it is way overkill for what I wanted. I wanted a simple tool I could use on Linux. I didn't find one, but I found Lunapic online and it works pretty well. It has a bunch more options, but crop was all I needed and it was right at the top.
Iaman told me about Peggo, which splits the MP3 soundtrack off of YouTube files. I don't have any use for it, not having an MP3 player, but I can see how it could come in handy. They are off-line this weekend for maintenance, but should be back soon.