I often take a couple of screenshots for a guide or to email to respond to a support ticket at the office.
Becoming tired of selecting every file and manually renaming them, or using apps that are perfect but are too complicated or have too many options, I wrote a quick script.
It does one thing: based on a chosen file name, it renames the selected files and numbers them starting from one. I trigger the script via Alfred, so it's basically: select files, trigger script, pick a name, done.
You can download it here.
(I found the icon online a while back. If it's yours, please do tell.)