Trello Attachment Editor
A static JS app that allowed you to authorize with your Trello account, fetch the board structure, find attachments, edit them in the browser then replace them in the cards.
Quite a nice thing. I believe it was done to help with naddr1qvzqqqr4gupzqwlsccluhy6xxsr6l9a9uhhxf75g85g8a709tprjcn4e42h053vaqyghwumn8ghj7enfv96x5ctx9e3k7mgqpqergdnrxgmnxdclvfm5y attached scripts and CSS files.