I am always looking for tools to help with my work as an attorney, faculty member and IT professional. Many pdfs have language that I would like to be able to change, but the traditional pdf tools are not up to the task. Infix PDF Editor has a large suite of tools. A favorite of mine is Find and Replace. It works just like the function in my favorite word processor. There is also a spell check and the various text formatting tools.
Other functions allow objects to be manipulated. Lines can be added, including those with color. This allows sections of documents to really stand out. There are also various drawing tools (as in Paint and similar programs). Finally, there are the standard tools one finds in Acrobat and other pdf programs.
PDF Editor is really remarkable because it combines aspects of different programs to allow one to edit PDFs as if they were a different form of document. I highly recommend Infix PDF Editor for editing tasks.
– Jonathan Warshay