Training
1RM calculator
You do not have to risk a true max to know it. Enter the weight and reps from a recent heavy set and the Epley formula estimates your 1RM, with a percentage table for programming.
Why know your 1RM
Most serious strength programs (5/3/1, GZCLP, powerlifting blocks) prescribe sets as percentages of 1RM. This estimate is enough for programming; save the true max test for the end of a cycle, with a spotter.
In the app: Tabata Timer by fit.how has these calculators built in, plus an interval timer you can read from across the gym. See the app.