There's a business idea: let users buy apps that cost $10 for say $2/month, 3 months minimum. Eat the risk of users cancelling, make bank on the large minority who end up paying 50 times. Add some dark patterns and confusing language to keep your margins up. Liberally claim fraud for apps where users consistently pay $6 but you're out $10.

If you could execute this technically it's clearly a billion-dollar idea, but maybe the only people with the right connections to do it are Apple and Google.

A reverse might also work: a platform that provides a prepaid plan in a transparent way. Let the user pay for three months in advance. Cut off the service afterwards if they don't pay for the fourth month. Bonus: provide a one-time purchase option too.

Add a $3.99/mo recurring subscription option.