In the instance of a customer not wanting to download the Stamp Me App, or they do not have a smart phone, it is possible that they can still take part in your loyalty program.
If you have a Pro plan, you can manage their account from your Merchant Console. From the Merchant Console, you can create members, apply stamps, see the number of active and all time stamps a member has, and mark rewards as having been redeemed. Many merchants choose this way of operating.
However, for the best user experience so members can see many stamps and rewards they have at any time, we recommend that they download the Stamp Me App.