HelloSign is a cloud-based electronic signature tool that enables users to sign, fill out, send, retrieve, and save documents paperlessly. HelloSign users may fill out and sign documents on a computer, tablet, or mobile phone. HelloSign integrates with cloud storage services such as Google Drive, Dropbox, Evernote, Box, and SkyDrive, allowing users to save and access their signed documents in any of their cloud storage accounts. In addition to its web application, HelloSign also offers a free mobile app for iPhone and Android devices. Heavily integrated with Google, HelloSign offers a Google App for on-boarding teams, provides the option for users to use their Gmail username and password to log directly into HelloSign, and offers “HelloSign for Gmail,” a Gmail extension that adds a "sign" button to all attachments received via e-mail, allowing users to open, sign and send documents from directly within their Gmail accounts. HelloSign also offers a REST-based API that supports JSON. API users can send documents by either referencing an existing template or including a file in their API request.