Since Firefox only accepts add-ons signed by Mozilla, you can't, under normal circumstances, install the add-on by feeding Firefox the zip created from files in my Github repository. Users should install directly from Mozilla's site. When you see the 'Add to Firefox' button, you can right-click to download the xpi file without installing and review the code. The xpi file is just a zip file with the xpi extension. You can change the extension and extract the files.

Update: If you want to get rid of junk on page, let me point you to Ublock Origin.