Adobe Reader is a Office Tools software developed by Adobe Systems. After our trial and test, the software is proved to be official, secure and free. Here is the official description for Adobe Reader:

BS Editor: Adobe Reader is free software that lets you open, view, search, and print Adobe Portable Document Format (PDF) files. The latest version of Adobe Reader includes additional features such as:
Provides better overall performance for faster launch times and real-time zooming and panning
Enables you to fill out and submit PDF Forms from a variety of devices
Helps you download and organize digital editions (formerly known as eBooks) on a variety of devices, with full support for portrait or landscape viewing
Lets you display and share Adobe Photoshop Album slide shows and electronic cards, and export images for online Photo Processing (Note that online photo services vary regionally.)
Allows you to save a range of files attached to PDF documents, such as word processing documents, spreadsheets, and Multimedia files, and open them in their native applications.