JPEG to PDF - JPEG to PDF is a free program that can convert image files to PDFs.
pdflayer - Free, powerful HTML to PDF API supporting both URL and raw HTML conversion. Unlimited document size, lightning-fast and compatible PHP, Python, Ruby, etc.
PDFill - Open, View, Edit, Save and Print PDF Documents without Adobe Acrobat
Doczilla - Effortlessly create stunning PDFs and screenshots. Seamlessly store them in your own AWS or Google Cloud Storage bucket, putting the control and creativity right at your fingertips.
Convert-JPG-to-PDF.net - Convert JPG to PDF for free with this online service.
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.