The Free Trial Surfing service was developed by Josh Browder - who was a teenager when he created the Do Not Pay algorithm to fight parking fines - who says while the platform isn't linked to a customer' bank account or credit card, it is still partnered with a major bank.
He told the BBC: "The idea for this product came when I realized I was being charged for a $21.99 (£18) gym membership from over a year ago that I was never using.
"In fact, I had completely forgotten that I had signed up for a free trial in the first place. Constantly trying to keep track of when a 'free trial' period ends is annoying and time-consuming."
To date, 10,000 people have signed up to the app since it launched six weeks ago in the US, and he revealed the two most common uses for the service were for porn and Netflix subscriptions.
The development lets customers use a virtual credit card number and invented name to sign up for a service, while the card is actually registered to Do Not Pay.
Meanwhile, the card won't work if anyone tries to use it to pay for anything else.
Browder added: "It took around six months to build. Right now we're testing it - maybe one day it will be a cheap subscription, like $2 per month.
"The reason it took so long was that we wanted to be sure it would be declined if it is used with a real purchase. We won't hold people to account - it will be us who takes the hit."