Firma Electrónica is a free Android app developed by RC Zone that provides a simple and easy-to-use electronic signature solution. With this app, you can sign documents using your finger and export the signature as a PDF or image in your gallery. You can then share the signed document via email, WhatsApp, and other apps.

The app has a straightforward interface that allows you to sign the document with a single tap. You can also adjust the size and color of your signature to meet your needs. Firma Electrónica is a useful tool for anyone who needs to sign documents on the go or doesn't have access to a printer or scanner. Overall, Firma Electrónica is a reliable and efficient app that does what it says it will do.