Fax Pro - Simple, yet delightful way to send & receive faxes on the go.
DocRaptor - As the only API powered by the Prince HTML-to-PDF engine, DocRaptor provides the best support for complex PDFs with powerful support for headers, page breaks, page numbers, flexbox, watermarks, accessible PDFs, and much more
Hellofax - Easy. Reliable. Online faxing. Send & receive faxes from anywhere.
PDFCrowd - Pdfcrowd is a Web/HTML to PDF online service. Convert HTML to PDF online in the browser or in your PHP, Python, Ruby, .NET, Java apps via the REST API.
vFax - Get a virtual fax number for as low as $2.99 per month and 3.0 cents per minute
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request