Adding members to your group can be done at anytime. Tap on the "Groups" tab from the bottom menu. Then tap on the "Type to add member" box, either during group creation or after.
**If creating a group over the Bivy Stick, the group will be created first, then individual invitations will be sent separately. This will take some time, so please be patient. Group invitations are not received over the Stick. If joining out of service, the best way to do so is with a code. Enter another Bivy user, email address, or phone number. Only the group creator can add or remove members; however, other Bivy users can easily join your group via the group’s unique code.