AppBlock Pro Requirements: 4.0+ Overview: AppBlock – Stay Focused is a free android application that helps you (its users) to block temporarily distracting programs on his mobile like Facebook, Twitter, Instagram, and addictive apps like Talking Tom or Angela, etc. so that you can stay focused in your work. The blocker app can get activated for a precise time and date, and once the pre-set time duration gets over, the barring gets automatically over.