On an iPhone or iPad
Open app.lynkosports.com in Safari. This does not work from Chrome on an iPhone, which is the usual reason it fails.
Tap the share button, the square with the arrow coming out of it, at the bottom of the screen.
Scroll down the list and tap Add to Home Screen, then tap Add.
You now have a Lynko icon on your home screen that opens straight into the app with no address bar.