These ECG Pro Pack apps have really been improving since recent updates. They are not designed as standalone tutorials, but rather serve as an excellent and extensive library of realistic example cases that illustrate principles of ECG interpretation, from the simplest to the very complex, and from the common to the very rare. Recent updates have expanded to include basic information on elements of ECG interpretation and cardiac physiology, which has added a new layer of depth to an already great collection of apps. Please, keep up the excellent work!