This is a two in one plugin, that collects payment via SagePay Form and SagePay Direct. By using this gateway we can collect payments via all major credit cards and debit cards. SagePay Form does not require an SSL certificate in your web store, but SagePay Direct will require an SSL certificate and offer many other functionalities like refund processing, etc.
This is the EXACT same plugin as distributed by the developer on WooCommerce. The developers’ links are provided above.