toPDF lets you upload up to 5 files (max 25MB) or point to remote files via their URLs and converts them to a PDF file which you can then download. Lots of file formats are supported, including Microsoft Office, HTML, JPEG etc.
Votiro lets you upload a file (PDF, JPEG, PNG, BMP, TIFF, GIF, WMF, EMF) of up to 64MB in size, which it will attempt to rid of embedded malware, trojans and viruses. The sanitized file can then be downloaded and viewed safely.
LucidPress lets you create flyers, brochures, newsletters, magazines and photo books easily from predefined templates. You can transfer text from a Google Doc, drop in a Youtube video, or import photos from Dropbox, Flickr, Facebook and Google Images easily. When your publication is ready, you can export it as a high-quality, printable PDF, or individual pages as a PDF, JPG, or PNG files. A free sign-up is required to use the tool.
Hemingway helps point out common readability errors in your writing. The errors are color-coded, so it is easy to locate and change them in real-time. Common errors include long/complex sentences, unnecessary adverbs, difficult words that can be simplified etc.
Text Mechanic is a massive collection of online text manipulation tools. This includes tools to remove empty or duplicate lines, extract a specific column of delimited text, add prefix or suffix into lines, find/replace text, sort lines etc. If you have a text manipulation need, Text Mechanic probably has the tools to help you with it.