0-20 Pullups Back Trainer is an Android app developed by Zen Labs Fitness and is available for free. It belongs to the Lifestyle category and falls under the Health & Fitness subcategory. The app provides a proven program that enables you to build and strengthen your upper body, and helps you perform specific reps of pull-ups with a period of rest in between. With this program, you can complete 20 pull-ups in just six weeks.

The app offers detailed instructions on how to do a "negative pull-up" exercise, which helps you build enough strength to do a proper full pull-up. It also allows you to repeat a certain day’s workout if you can’t physically finish it and skip ahead to any day you wish. The app is easy to use and straightforward, with voice cues that guide you through the exercises. Join the community for help, tips, and advice on Facebook and Twitter. Zen Labs Fitness is a proud supporter of the National Breast Cancer Coalition and donates to their cause.

Please note that this app and any information given by it or by Zen Labs LLC are for educational purposes only and are not intended nor implied to be a substitute for professional medical advice. You should always consult your healthcare provider before beginning any fitness program.