Paul Kinlan, developer advocate for Chrome and the open web at Google writes:

Chrome implemented window.onappinstalled event. It’s triggered when a user installs a progressive web app via the Add to Homescreen API or now more importantly via the manual method of Add to Homescreen.

This is a very useful addition because it allows you to see engagement on the prompt vs people who use the system banners or menu buttons to install a progressive web app.

Now you can track your PWA’s install engagement based on the method of install — via the prompt or manually via a custom prompt. Read the docs for more details.

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