PDF tools for a cup of coffee (or free) on chromebooks

Do you still remember the times when you had to buy expensive software just to get small things done? E.g. Acrobat software of Adobe just to manipulate pdfs? Do you remember that operating systems and computers were expensive? This time is definitely over.

With a chromebook and a cool cloud tool you can manipulate pdfs as well. Have a look at smallpdf.com. The best tool I found to manipulate pdfs in many different ways.
Do not forget to donate a coffee for the programmers!