iOS beta testing

Hello!

I'm found of new technology and features, so I like to test different cutting-edge products on my devices. Unfortunately, I can't buy all subscriptions to every product of every vendor.
So is it possible to beta test your products full functionality without spending money? Do you cancel all purchases after beta testing is over? I have iPhone 8 so I'm interested in iOS products. Do you use TestFlight so that beta testers don't have to worry about spendings?

Best wishes,
Brian