Document Signing Software Development

I'm looking for a document signing software that can seamlessly integrate with my primary tools: Salesforce and Gmail. It should be capable of handling various types of documents, including contracts, agreements, invoices, and letters.

Key Features:
- Integration with CRM and email tools like Salesforce and Gmail
- Support for merging fields
- Notes/memo segment
- signature Tracking
- approval feature for visibility

Ideal Skills:
- Software development with CRM and email integration
- Experience with creating document signing software
- Understanding of Salesforce and Gmail APIs

Please reach out if you can meet these requirements. Thank you!