To search for existing friends:
You can search existing friends using the following criteria mentioned below. Select the Profile > @Icon > Tap Find Friends.
-Name and Location (e.g Amy in New York).
-Email (Exact match)
Inviting friends to use Insight Timer:
Inviting new friends to use the app: Profile > @ icon > Enter the email address into the 'Invite friends' field and select 'Send'.