Elapser for Android
Using simple statistics, the app logs different activities and calculates the average time and standard deviations of the time intervals between their occurrence.
When a time of average minus one standard deviation has elapsed, the app turns the event button red to let the user know that it's possible that it is pending.
For example, some things this app can be used for are timing typical daily chores and tasks like getting gas for the car, exercise routines, random social events like weddings and funerals etc..