On the whole, Sejda is a pretty polished product, but the text editing side of things is a little disappointing. Depending on your needs, it may be enough, and the rest of the tools here are top notch ...

Gimp is normally used to create or manipulate images files, but can also work with PDFs if you understand how it works and what it's limits are. If you’ve never used Gimp—a free image editor available ...