When I create a new project in my free, basic account on the website, I can add MANY layers - I am not sure it’s unlimited but I stopped trying after ~8.
In the latest version of the iOS App (1.0.58, downloaded 1 Nov 2023) I can only add 1. Trying to add a third layer results in a splash screen demanding an upgrade.
App is not replacement/alternative for web version
It is bonus feature for ppl who did buy subscription
While leaving you option to try it out for free with some features limited