About ArduPilot Discourse Chrome webpack

does anyone know how did I manually trigger the installation under the Windows and Android systems? It was triggered randomly when I surfing the forum pages. It suddenly prompted and I chose yes to install. How do I manually trigger intentionally for other devices? Unable to find the App in the Google play store.

I tried searching the internet but failed to find anything useful.

See top right in the screenshot. In Chrome for Android you need to tap the burger menu and find the install option there.

It is just random, one mobile phone got alerted and installed, another mobile phone, nothing happened.