PDFGear:
Heard about this app last week and tried it out, free and great. Make sure you download the PDF converter app as well and the PDF scanner HD, a total of three integrated apps. All are free, very easy to use, complete and very thorough. I currently also have a subscription to PDF Expert Pro. Great app but not free. I use the cloud to store all my PDF’s for ease of retrieval. I also import some such as manuals to Apple Books for easy access and reading. Since they are PDF’s you can mark them up and book mark them as well. Not only highliting but actual on document side hand written or text typed notes.
PDF Gear