Putting an App in Stealth Mode

[Caravaggio]

This is my case scenario:

once my app is installed in a mobile device i need it to be stealth: no track of the app shall be visible on the phone, until the phone owner calls a certain 4 digits number at which point the app main window or/and app icon becomes visible and operative: would this be possible to achieve with b4a and could anybody plz point me into the right direction (library or/and code) in order to code such a feature?

Thanks in advance.

 

[Erel]

You can create a service that start to run at boot. In order to keep it alive you will need to use StartServiceAt and schedule it to run in the next minute each time.

I'm not sure how will you be able to reliably catch the phone call. Maybe you can use another application or activity (simple calculator for example) which will allow the user to have access to the service.