My little Chrome extension https://unshorten.link has had a growing user base for several years now. Like a few others in this thread, my strengths don't necessarily lie in advertising or marketing. I'd be open to bringing on a partner who has experience monetizing and marketing projects like this or even selling outright to the right buyer.
As a security professional, I'm wired to loathe shortened links. This is a great example and exactly why I created a little hobby Chrome extension to expand all shortened links for inspection - https://unshorten.link
It'll expand a goo.gl link which would then display the Grabify link. The extension does not support Grabify but will certainly be adding it. I'm not a fan at all of these IP trackers.
I work in security and have a paranoia of shortened links (bit.ly, t.co). I got frustrated with the options out there that forced me to right click every shortened link or paste it into a site so I made this Chrome extension / web app. It is pretty simple and keeps a list of 300+ shortened link services to check against. If your browser ever visits one it redirects you to the site to expand the link. It will also hit the Google Safebrowsing API to see if it is known to be malware plus will strip out tracking cookies.
It's been fun and rewarding watching my little extension grow to global use of over 4k users.