The Perka app is only available for Merchants on the Clover POS.
If you're a Clover Merchant in the US, you can download Clover Rewards here. This will allow you, as a Merchant, to offer a loyalty program tailor fit for your business. If you're looking to receive feedback from your customers, check out Clover Feedback. Alternatively, if you'd like to send out emails and sms promos to your customers, check out Clover Promos, which integrates directly into your Clover Customers app.