BluePay Payments
Use BluePay for credit card processing your invoice payments.
Advanced Line Item Editor
Adds advanced editing to your line-items.
Canadian Invoicing Requirements and Customizations
Adds GST and HST tax to line items. Could be adopted to modify different types of taxes.
PayPal Payments with Express Checkout
Accept Paypal Express payments for your invoices. Including invoice deposits.
Advanced Form Integrations: Ninja Forms, Gravity Forms, Formidable, & WP Forms
Use your premium plugin based form to accept estimate requests that integrate with Sprout Invoices.