Libros SEP is a free Android application developed by Abelinux. It is an educational and reference app that offers access to a digital library of textbooks published by the Mexican government. The app provides easy access to textbooks for primary, preschool, secondary, telesecondary, telebaccalaureate, and indigenous education levels.

The app's user interface is straightforward and easy to navigate. It allows users to access the textbooks anytime, anywhere, without having to carry physical books. The app also features a section where users can check the important events for the week.

It is essential to note that the app aims to provide easy access to the textbooks for educational purposes only. The app does not allow users to share or distribute the textbooks to protect the copyright of the publishers.

Overall, Libros SEP is a useful app for students and teachers who require immediate access to textbooks. The app is free and provides a comprehensive collection of textbooks published by the Mexican government.