While the Perka mobile app is optimized for iOS and Android users, anyone with a cell phone can still earn and redeem perks. Customers can use the Perka sign-up receipts to create their account through text message.
When the receipt prints, give it to your customer and they'll text the three-word code to the phone number provided. When they have enough points, they'll receive a message with a QR code that you can scan using your Clover device. Additional instructions for scanning a code can be found here.