As your programs get bigger, more complex and better overall, I think we would all agree on a HUGE update, being an automatic-update...updater. I don't know how this would be done, but I do have a simpler way:
Upon clicking the "Check for Updates" option in the right-click options pane, the web browser would direct itself to the newest file, and that file would show up in the "download file" dialog box window saying the file's name (ex. screenshot_captor) followed by the version (2.xx.x).
All you would have to do is have the web page redirect itself through to the newest version-
a bit of work, I know, but maybe it could be an option for donators only?
As always, keep up the great work,