The mobile app itself is free and is published both for Android and iOS. For a minimal amount, you can upgrade the app to gain access to GPS guided travel articles with an embedded high resolution map pointing out the destinations mentioned in the article—plus GPS navigation assistance! The best part? You don't need the internet to read the article and use the maps. With this app and your map reading skills, you will never get lost.
No WiFi? No Data Plan? No problem.
To introduce you to this very useful app, click on either (or both!) of my two articles for GPSmyCity—Exploring Georgetown in Penang and Taipei: An Artist's Playground—and it will take you to the article, then click on upgrade to access the offline maps. The upgrade is FREE from July 11 to July 17! (If you haven't installed GPSmyCity app yet, it will prompt you to install the app, then once installed, it will direct you to the article.)