My.Club has a web app.
When you install the web app, you can see it in your phone, just like any regular mobile app.
The difference is, when you launch the web app, it opens My.Club in your mobile browser. That's it.
But you can use My.Club as normal, with all its functionality intact. And it's always just one tap away.
iOS: use the Safari browser
You can wait a couple of minutes, and you will see a banner offering you to install the web app
OR
In Safari, at the bottom, tap Share button 
> Add to Home Screen
Android: use the Chrome browser
You can wait a couple of minutes, and you will see a banner offering you to install the web app
OR
In Chrome, in the top right corner, tap three vertical dots ⋮ > Install app