Monosnap not only works on OS X, but also Windows and others. You can upload directly after recording or capturing.
Ranked in these QuestionsQuestion Ranking
Pro Easy drag and drop saving and uploading
Pro Annotation tools for both screenshots and during video recording
Pro Screenshots and Screencasts in the same app
Nice to have one less app running all the time.
It costs nothing.
Pro Able to upload directly after recording or capturing
Very convenient especially when doing stuff like writing documentation or blog where you can just paste the hotlink directly.