The app helps you perform Lactate Threshold and FTP tests and calculates your ideal training zones.
For those without a heart rate sensor the app also has a heart rate training zone calculator based upon age and resting heart rate.
Notes:
For LTHR testing you require a BTLE or Ant+ heart rate sensor such as the Wahoo Fitness heart rate strap to use the heart rate monitoring features. Ant+ sensors require the Wahoo Ant+ key.
For FTP testing you need an Ant+ power meter such as a Powertap G3 or Quarq. It has not been tested on BTLE power meters, but it may work. Ant+ sensors require the Wahoo Ant+ key.