Check out Reformed Companion on the Google Play Store or Apple App Store. Your go-to source for your favorite Reformed catechisms, confessions, creeds, and more. The catechisms include proof texts from the ESV Bible translation, as well as a quiz feature to test your catechism knowledge. Very useful and edifying! Thank Clayton Larson for all the labor he put into making this.
This app has an intuitively designed graphic user interface. Very user friendly.