A live wallpaper with ECG waveforms changing based on battery level.
The wallpaper cycles through ECG hearth rhythm of Normal Sinus, Ventricular Tachycardia, Ventricular fibrillation and Asystole when phone is on battery use with settings for each rhythm. As the phone charges the rhythm shown is Supraventricular Tachycardia.
You can select the color of each rhythm along with a host of other settings when setting the wallpaper.
Heart rates are as follows for each waveform:
Normal Sinus 60-100