For Apple Devices:
On your iPad or iPhone, open Safari and navigate to your account.
Now, tap the "Share" icon. This may be located at the bottom middle of your screen or in the upper right corner.
On the share menu, scroll the list of gray icons to the right and tap the "Add to Home Screen" button. An "Add to Home" screen will appear.
On the "Add to Home" screen, just tap the "Add" link in the top right corner.
For Android Devices:
On your Android tablet or phone, launch Chrome and navigate to your account.
Now, tap the menu button and select "Add to homescreen."
You're all set! Now you have a new "app icon" on your homescreen to tap whenever you want to access your account.
This should work similarly on another browser as well. Just look for the option to "Add to Home Screen" under your browser menu options.