A super simple donation add-on for xenForo. Requires manual updating of the progress bar when you receive donations. Supports any donation system (ie. Paypal) that gives you HTML buttons to be rendered, paste it in the add-on options.
Go to install add-on in xenForo, choose the file from "install from uploaded file" and hit install add-on! Then go to xenForo > options, find "♦ Simple Donations" and set up the add-on.