Home screen widgets that show how much data you've used/have remaining for the month, display live data usage by apps running, and your apps that use the most data; Awards you badges based on your data consumption, ranging from Absolute Beginner to Data Tamer Where It Excels. We've mentioned Onavo for Android before, and its iOS cousin.
There can be electrocardiogram (EKG, ECG) changes associated with low potassium, and sometimes the diagnosis of low potassium is made incidentally by finding the characteristic U waves on the EKG tracing. In severe cases, hypokalemia can lead to dangerous disturbances in heart rhythm (dysrhythmia).
Hypomagnesemia is often times associated with hypokalemia; thus it is important to check a magnesium level in any patient who presents with arrhythmia. Severe hypokalemia with EKG changes should be treated emergently with repletion with intravenous potassium chloride to a K of 4-4.5.