As you can see from the other reviews, this program works for some people and doesn't work for others, kind of like how everyone else can log in to the Zoom meeting except for Carl. But Carl is also the same guy that regularly accidentally "replies all" to company wide emails and last year managed to crash our internal servers despite working in public relations.
Yes, if you are log in to more than one Google account Flookup doesn't like it. Yes, if you share your sheet with someone and you don't have an enterprise plan it will not work (though it does appear if the other users only have "view" access Flookup doesn't mind.) But these are necessary security steps so one user can't share this freakin awesome program with other people. Plus you'll get a support response within hours for any issues you have. But first read the really complete FAQ and doc files on the website.
This app works great—quick and easy to use. Nice work.