For now, it is not possible to acquire multiple tickets. The app is only valid for the main passenger. However, you can buy tickets for fellow passengers in advance via the timetable query.
Please also read the following articles:
- Can I also buy tickets for fellow passengers?
- Can I use the app to purchase a ticket for my bike or for my dog?
For your children/grandchildren
If your child/grandchild is under 16, you can get a Junior Travelcard or a Children's Co-Travelcard. With one of this card, which costs CHF 30.00 per year, your child/grandchild will be able to travel free of charge, when they are accompanied by an adult with a valid ticket.