For iOS Safari:

1. Tap the Share button ios_share
2. Scroll down and tap "Add to Home Screen"
3. Tap Add in the top right corner

For Android Chrome:

1. Tap the menu button more_vert
2. Tap "Install app" or "Add to Home screen"
3. Confirm by tapping Add

Install this app:

Look for the install icon install_desktop in your browser's address bar.