FirmaSAT enables you to analyze and sign CFDi digital tax vouchers (Comprobantes Fiscal Digitales) as specified by the Servicio de Administración Tributaria (SAT) in Mexico.
2024-10-10: 
New version 10.70.35.
2024-06-19: New version 10.70.30
with support for complemento Carta Porte v3.1.
Why do I have to pay a setup fee?
How to create a Cancelación CFDI versión 4.0
I get an error when I try to sign an XML document. How do I fix this?
Using diQRcode to
create a QR code for a CFDi v4.0 document.