Save the app on your cellphone/tablet
Step 1:
Go to your iphone or ipad's browser with the homepage of the website loaded.
Step 2:
Click the arrow on the bottom of your browser
Step 3:
After clicking the arrow, a pop up should have appeared.
In the pop up, "Add to Homescreen" should be one of the options. Click that.
Step 4:
Write whatever label you want to see for the website's icon
Then the icon should pop up in your homescreen like a regular app. And you should be able to open and use it like a regular app.
Step 1:
Go to your android cellphone or tablet with the homepage of the website loaded.
Step 2:
Click the three dots on the top right side of your browser
Step 3:
After clicking the three dots, a pop up should have appeared.
In the pop up, "Add to Homescreen" should be one of the options. Click that.
Step 4:
Then another pop up will come up – click Install App (or create shortcut, if you prefer that)
Then the icon should pop up in your homescreen like a regular app. And you should be able to open and use it like a regular app.