neo.tax - automated R&D tax credits for startups = extra month of burn
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
Stripe Atlas Taxes - Help file your business taxes
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
1099 Tax Forms by Payable - Automatically generate tax forms for contractors
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.