This would eat the app store alive and I could not be happier. So many very basic and simple, frequently cloned, but sometimes necessary apps exist out there that do the whole trial and subscription song and dance to collect rent. This is only because there is no path for open source alternatives. If there were, it would be like the state of affairs with desktop based software, where you have some first party solution, then on github there are typically a couple open source free alternatives if there is any demand for that sort of software, or there are even whole ecosystems like apt, brew, or conda to maintain open source software on your device.