Do you think its possible to build a webpage Hidden/Transparent/Invisible/MIDI/GRID/App, that can.. (wait for it)..

1. Offline, (within an environment) Users agree to EULA and install the App via FREE WiFi Signal, Accessing a React Webpage.
2. App is "installed" yet, invisible (accessing a hidden URL) .
3. The App Triggers MIDI Sounds as users poke/touch/swipe/access their Smart Devices.
4. My Question is...
5. Being an invisible, top, z-index layer. Can users still maintain access to their device as usual? Or my concern is that it won't be possible to interact as-usual with their smart device if an invisible layer somehow limits access to the other functions on their device screens.
6. My Intention is to develop an app that Always Triggers MIDI Sounds, (which are only [volume] controlled at the "head" localized-LAN Server).

Thank you,
Buddy Jackson

GitXome!

PS: I always create the Art way before the Product..
..and oftentimes I forget what I've created!