Launching Mini Program from a mobile app means that users can redirect to a specified page of a Weixin Mini Program from a third-party mobile app that has accessed this feature and redirect back to the original mobile app after the completion of the service process.
The feature of launching a Mini Program from a mobile app is open to all developers. Developers can obtain the permissions to this feature after applying for a mobile app and getting the approval under the Weixin Open Platform account.
The approved app can be linked to the Mini Program in Management Center > Mobile App > App Details > Link Mini Program Information.
For mobile apps and Mini Programs under the same Open Platform account, redirect between them can be finished without linking. Otherwise, linking is required.

A mobile app can only be linked to up to three Mini Programs at a time and three times per month. A Mini Program can be linked with 500 mobile apps.