Custom Moodle Apps
Unfortunately, the core team does not have the resources to help people use the open source code to build custom apps.
MoodleHQ provides a service where they can customise the app for anyone who needs it including the Push Notifications service management with Airnotifier. This service also helps fund the overall development of the app: moodle.com/branded-app/.
If you're still considering making your own custom app, you can read the rest of the documentation in this wiki to understand how the application works and you're also welcome to ask for help in the forum or read the legacy documentation (no longer maintained).