Real PDF is a totally free PDF reader and editor app. Compatible with Adobe Acrobat Reader, Foxit PDF, Xodo PDF, Plaris PDF, Google PDF, Drawboard PDF and PDF X, Real PDF provides a full set of features of viewing, printing, editing and annotating PDFs.

Formats Supported: PDF, PS, Tiff, CHM, DjVu, Images, DVI, XPS, ODT, Fiction Book, Comic Book, Plucker, EPub, Fax

Features details:
VIEW
• Horizontal or Vertical scroll, Single Page or Continuous Scroll Mode.
• Search text, zoom in, zoom out & Presentation Mode.
• Thumbnails and Bookmarks

ANNOTATE
• Adding annotations, removing annotations, editing annotations
• Markup with highlight, underline, strikeout.
• Add text comments, text boxes, and hyperlinks to PDF files.
• Freehand-writing and drawing.
• Signatures

FILL FORMs
• Directly fill the interactive PDF forms.
• Use Typewriter annotation to fill the noninteractive PDF forms.

MANAGE
• Thumbnails, reviews , bookmarks, and annotation.
• Share and print PDF documents.
• Quickly access the files recently opened.

Real PDF is a free and open source software under GPL V2.  The source code can be downloaded here.
Better Audio Editor is based on open source project Okular.

No, it’s not a have-to. The app is free for everybody to use for any purposes. Although we encourage users to give us a fair review and rating on Windows Store, you can always skip the window by clicking the “Skip” button at the left bottom corner. In addition, you can check the checkbox “Don’t show this again” if you are sure about it, as displayed below.

For more questions, please read our text only quick-start guide below. It’s a more comprehensive user manual.

Real PDF quick guide and online tutorial.