Project Panorama is a fully featured Project Management solution for WordPress.
Slate is alternative design for your invoices and estimates that’s free for everyone!
Provides IVA & IRPF tax options and additional customizations for legal requirements.
Provides EU Invoicing Requirements including Tax Rules
If you’re an Australian Sprout Invoices user than this add-on is for you!
Adds GST and HST tax to line items. Could be adopted to modify different types of taxes.
Adds VAT & is an example framework for custom Client meta.
Accept Paypal Express payments for your invoices. Including invoice deposits.
Caldera Forms integration is the most advanced form integration available. All for free.