Plank challenge app for android description: 30 days of plank trainingthis app helps you keeping track of your plank exercises for a period of 30 days.
Features 30 day workout plan workout timer with exercises for plank right arm plank and left arm plank from 20 to 300 seconds in 30 days.
Post workout to facebook additional workouts for download (different levels squat challenge ab challenge 7 minute workout etc.
)Free to use but ad supported.