A free program for Android, by Zoho Corporation.

Zoho Sign is an electronic signature service that lets you sign and share contracts, promissories, and other agreements using your mobile device. The app lets you create, sign, and share contracts, and it’s secure, easy to use, and fast. It works on cloud and integrates with your apps for a seamless signing experience.

You can sign a contract in less than 3 minutes. Simply take a picture of the document and upload it. You can add a signature, make changes, and send the document for signing. Once it’s signed, you can share it with anyone, anywhere, in just a few clicks.