You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature may not be available in some browsers.
Worth noting that the credit for referring someone does not get applied until after the referred person has signed up to the subscription. So anyone referring who is only on the trial, will not (unless the referred trial is upgraded to subscription early) get the benefit of that referral until after the decision to subscribe needs to be made. Not an issue if the referrer then subscribes, but if they don't, then the credit will be lost. And would have been better used by someone already a subscriber.