xodo

Absolutely free PDF viewer and annotator for iOS and Android. You can easily navigate through the pages, mark text, add your handwriting and text using Xodo. App supports other formats of office files like .doc, .xls, .ppt, etc. Also you can use premium version of Xodo. It allows PDF editing, but you don’t need it, because planners in PDF works fine only with annotating mode.

If you have any questions about working with Xodo please look at Official FAQ.