Name: Plank Hero
Rating: 4.8 (48 reviews)
Author: Strafe

Plank challenges! Track your progress and compete with friends. Default leaderboard can be changed from the global leaderboard to a private leaderboard group you share with your friends. See who the leader is for the week, month, and year! Check your log to see your progress over time. Daily reminders can be configured to get your goal and streaks for continuous goals met.
Watch vibrates each 15 seconds and a longer buzz happens at 1 minute intervals.
Start the session, the timer will accumulate your time, and then end your session. 
The world needs more abs, be a hero!