I want a FOSS option for customer forms stored in a database (legal waivers). Brooklyn Cat Cafe is using Google Forms which has an option to store results in a Google Sheet, that has grown so big it has difficulty loading, as in, it takes forever, on many devices (at least that's the hypothesis). Some devices seem to load it more easily.

Searching, I found TellForm, which has become OhMyForm. I can't find any instructions for its use. How do I install it on the server? Anything they mention has not to do with that. It's probably in the download documentation.

I look for a cpanel app. Anything on there has got to be easy to use? There's just the basic tools for expert users. On Softaculous, I find “Form Tools”:

“Form Tools is a PHP / MySQL script that provides any existing web form with a backend database and a user-friendly interface to manage the form submission data.”

However, the best solution would be to stick to what they are used to, which is Google Forms. Here's an interesting article:
https://stackoverflow.com/questions/28655570/google-form-output-to-remote-mysql-database

Affordable option of $5 per month or $50 per year, assuming you have gsuite:

https://formdirector.jivrus.com/pricing
https://gsuite.google.com/marketplace/app/form_director/824044380012

Meanwhile, they may try a few tweaks to make the sheet load faster:

https://www.benlcollins.com/spreadsheets/slow-google-sheets

Lyvann at the cafe mentioned that there are too many people logging into the sheet, so that may be one of the issues?