The app, which uses the phone’s accelerometer to detect when the vehicle is in motion, works automatically.
"There's the alert at the top and if you click into the alert it asks you if you remember the kids, you can say yes, or no kids today," King explained. “Within three minutes after your trip is over it will alert you.”
King said since its release earlier this month, the app has been downloaded more than 200 times.
"A lot of people think it has to be 100 degrees outside for it to reach a level that's dangerous for a child, but actually it can be as low as 57 degrees outside the car," King said.
The potentially life-saving idea costs $1.99 in the app store. King said he is currently working on an Android version.