3.1.0: Added 2 questions. 3.0.0: Updated for Android 8.0. 2.4.1: Fixed Google Licensing for Android 5.0 (Lollipop). 2.4.0: Updated text. 2.3.0: Added new book. 2.2.0: Updated text. 2.1.3: (1) Improved tablet support, (2) Updated buttons. 2.1.2: (1) Update links, (2) Correct Google Play licensing. 2.1.1: Correct Google Play licensing. 2.1.0: Added 6 questions. 2.0.1: New internal folder structure. 2.0.0: Standardised text formatting.