I'm always sceptical of so-called "drop-in things". PHP Plumber is supposed to contain "Drop-in create, read, update and delete functions" -- what is that even supposed to mean?
But the bigger issue for me is that there is practically no license information. It's supposed to be built ontop of Laraval, but what does a buyer actually get? Can I use one license for all my projects? Do I need to buy it for each project? Is it anually? What about use in non-commercial projects? Am I required to put a credits link somewhere?
Considering I get something similar by just slapping Laravel + a few bundles + Bootstrap together, I don't think this startup idea could fly, much less could substain a business for a longer period of time (and if I bought into it, I certainly wouldn't support to be dropped a year later because you go out of business).