Keep the app open in the background

  1. Connect the database directly with the app, see fot example App Inventor Tutorials and Examples: MySQL | Pura Vida Apps

  2. Write a procedure, which checks the database, use the notification style extension to send the notification and get it running in the foreground first

  1. Try the itoo extension, read the complete thread and try the examples to learn how the extension works
  1. Get it running in the background. For questions about itoo ask in the itoo thread and provide a screenshot of what you tried

Taifun