With the stengerApp you have all the advantages of Stenger on your smartphone with you - and some added value in addition. Show my customer card: With this function you can identify yourself as a regular customer of Stenger. Your card becomes redundant. Get your exclusive benefits directly pushed to your smartphone. This way, you can benefit directly and immediately from your advantage vouchers such as € coupons, giveaways and discounts and redeem them directly with the app. My invitations: Y