must you buy a subscription

No. The Ninox App(s) are stand alone Apps and don't require a subscription.

Birger

But If I dont, this message will be always appearing, right?

I think you need to logout in order to dismiss the screen above.

No, the screen above continues regardless

And this ? :

https://ninox.com/en/forum/technical-help-5ab8fe445fe2b42b7dd39ee7/canceling-subscription-5ad8fdcf9604777a78f8d171

Even though the Ninox Apps, not including the browser version, are stand alone apps, there is a subscription fee if you use the Ninox Cloud service. Do you need the Ninox Cloud service?