BoosterHub no longer sells standard credit card swipe devices but they are compatible with the BoosterHub App.  Swipes must be physically connected to your phone, tablet or iPad and can be used only with the App version of BoosterHub.

You can purchase swipes via Amazon

You may also need to purchase USB adapters.  Here are the three options:

USB to Lightning
USB to USB-C
USB to Micro USB

Full featured Tap-to-Pay credit card devices can be purchased in BoosterHub by navigating to Settings→BoosterHub Settings→Purchase Credit Card Devices.