I have been having quite a bit of fun creating PHP scripts for Code Canyon with a Flat File database. This is a great solution for those that can run PHP, but are limited or do not have access to a MySQL database.
My latest item approved on Code Canyon is userResponse Flat File User Control System, designed specifically for User Access Control allowing you to add Access Authorizations to your front-end pages.
userResponse is easy to install and set-up, and adding Access Authorizations to your front-end pages is pretty straight forward. As with all of my scripts, I put a ton of love into userResponse. I wanted to keep it light, simple and easy to use so I did not add a ton of features. My goal was to create a system that just about anyone could easily use, and I think userResponse fits.
Think userResponse will work for your needs?