It’s an interesting thought, but he misses the #1 problem with online subscriptions- sign-up friction.
If you could just push a button and instantly be charged something, an awful lot of people would do it.
But when you go from $0 to $0.01, you will lose 99% of people, because most people can’t be bothered to fill out a form, put in their credit card number, etc. Even if the amount of money involved is absurdly small, it’s not the price, it’s the friction.
Now if he integrates the app with Apple Pay or Google Wallet that will help, a little. But only a little.