We are making an app for a health company who wants all of their patients to have this app, and are wanting to put it for free on the Apple and Android store.
But they want only their patients to be able to open it. For example the patient downloads the app, app opens and asks for code the user puts in the code which is given by the company(once and only once to open and unlock the app) and the user now has access to the app and every time they open and close out of the app, they do not want the user to have to put in a code every time.
This would make the app free and accessible to their patients but not to anyone who randomly decides to download and look at it.
We know how to put the lock on it and have the correct code unlock the app. How do we set it so it only needs the code once at the initial download?