Linux Reference Free is a useful mobile app that allows users to learn Linux while on the go. It is a universal application that runs on both mobile devices and tablets. The app is designed to provide a comprehensive reference guide to Linux, with features that enable users to view content offline, test their knowledge with quizzes, and easily zoom in or out to view images.

One of the notable features of Linux Reference Free is the quiz section, which enables users to test their understanding of Linux commands. The questions can be flagged for later review while the quiz is in progress. Once the quiz is over, the correct answers, along with the explanations, are displayed. User answers are also displayed, and questions that are left unanswered do not reveal correct answers.

The app is free and does not contain any ads. Additionally, no permissions are required, and an internet connection is not necessary to use the app. However, users should note that the text-changing icons won't show up on Android 4.0 and below versions.

Overall, Linux Reference Free is a handy reference app for anyone who wants to learn Linux. Users can give feedback and suggestions to the developer at and report any problems they encounter. Negative feedback in the comments section should be avoided.