Parents can invite family/friends via their BackThen App.
Step 1: Please tap on the invite button on your timeline (circled below):
Step 2: Choose to invite from the contacts you see in the list or enter their name or type email address in the field below 'Choose contacts'
Step 3: Tap on 'Next'
Step 4: Choose for which children you would like to invite them
Step 5: Tap on 'Invite'