For anyone on a Mac: all of these features in the screenshot are free with Preview. I assume OP is not, but something people should keep in mind.
I wish this got talked about more, Preview is both crazy good and free. You can split PDFs apart, merge multiple different ones into one file, use password protected files, edit and annotate them, add your signature, and so much more. Best of all, it just works, all the time.
I can also recommend Skim (free and open source) for macOS for some additional functionality [1].