Wondershare PDFelement - All-in-one PDF editor
Monosnap - Monosnap is a comprehensive screenshot taking software system that provides users with a fast and accessible way to take screenshots whenever they want. Read more about Monosnap.
Google Docs - Create a new document and edit with others at the same time -- from your computer, phone or tablet. Get stuff done with or without an internet connection. Use Docs to edit Word files. Free from Google.
Annotate - Annotate (formerly know as Glui) is the simplest way to capture, annotate and share screenshots.
Foxit PhantomPDF - Edit PDF files with our feature-rich PDF Editor. Download Foxit PDF Editor to convert, sign, scan / OCR & more. A speedy PDF Editor alternative to Adobe Acrobat.
LabelMe Annotation Tool - LabelMe is an annotation tool writen in Javascript and Perl for online image labeling.