Tablets with an internet connection are optional, but recommended. They're used to display digital waivers forms to people entering your gym, and they're used together with a barcode scanner so members can check themselves in. You don't need expensive iPads to run SportKeeper.
In fact the automatic checkin module requires an Android based tablet!
For the recommended setup you'll need the following:
(1) - Android based tablet, in automatic checkin mode, connected to an automatic barcode scanner
(1) - Or more, Android or iOS tablets, running the kiosk mode, always displaying the waiver form