Do I need a back-end for a single player F2P game?

Question

Mobile development

Good afternoon friends!
We decided to stir up a mobile game here. And the question arose, can modern single-player F2P games do without a back-end? Do Google and Apple services provide an API for working with ratings and purchases of things, etc.?

Answer 1

Rating: it is calculated according to its own formulas and cannot be standardized in any way.
Shopping: No back-end is needed for this (although you can pull information from your server if you wish, and not from the shopping API).
So the back-end will be small, because 99% of the work is on the client, but it will be.

Answer 2

If you do not plan to develop functionality towards the network, be it multiplayer, changing prices and some in-game parameters, then no