A free program for Android, by National Geographic.

Experience and see the world in new ways with the National Geographic app for Android. The official NatGeo app allows you to access stories that reveal insights into cultures, ideas, and discoveries — whenever and wherever you want.

This application offers the following features:

Sample content for free accounts
Offline reading of materials and articles
Unrestricted access to captivating stories and photo galleries for subscribers
Exclusive contents, monthly special features, invitations, and benefits for subscribers
Personal list of stories for easy access or reading later
Ad-free experience
Access to the latest stories, as well those that have been published and archived