GetAccept - GetAccept is a Sales tool for electronic signatures and sales document automation.
Adobe Acrobat DC - Make your job easier with Adobe Acrobat DC, the trusted PDF creator. Use Acrobat to convert, edit and sign PDF files at your desk or on the go.
Signaturely - Super simple eSignature software
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
SignEasy for Gmail - Sign documents or collect signatures directly within Gmail
Wondershare PDFelement - All-in-one PDF editor