Install the app on iPhone

Add Feels Life to the Home Screen in Safari. The site opens full screen, without the browser bar.

1
Find the Share button
Open the site in Safari and tap Share — the square with an arrow pointing up. On newer iOS versions it is usually at the bottom of the screen; on older ones, in the top Safari bar.
The Share button in Safari on iPhone
2
Choose Add to Home Screen
In the Share menu, scroll down and tap Add to Home Screen.
Add to Home Screen in the Safari menu
3
Confirm the shortcut
You can change the name if you want. Then tap Add in the top-right corner.
Confirming the shortcut on the iPhone home screen
4
The app on the home screen
The icon appears with your other apps and can be moved like any shortcut. Tap it to open the site full screen, without the Safari bar.

Notes

Installing is not enough: you also need to sign in inside the app, the same way as on the site. Adding the shortcut and signing in are separate steps.
On iPhone, sign in again inside the app after installing: the Safari session is not carried over.
The shortcut runs through Safari, but opens like a separate app.
An internet connection is required.
You can turn on notifications in your profile after installing.