The Android GMail app's notification of new emails is / used to be unreliable, so I created this web app to solve that problem. For that matter, it was or still is unreliable at pulling new messages. It was definitely unreliable years ago (2017). I haven't tested lately, but I am fairly sure there is still value in this web app. I use it all the time in early 2022. Once I got it doing what I wanted, I saw no need to rely on the app.
This (web) app pulls at your request, it does not push--that is, it does not notify. It gives you a reliable count of unread messages when you ask it.
The source code is on GitHub, and you're welcome to run this on your own server, so I don't have access to your "stuff." If you proceed below, you'll be taken to Google and asked to give my app read-only, metadata-only access to whichever GMail account you want to check.