I actually have a solution that costs exactly $0.01, per employee. It also works on any platform.
Not really. If you were flipping the penny to get heads or tails and lost it, you could easily replace that penny with a coin, a washer, a stick from outside, a book...hundreds of things already around your home or office, many with no use or value. You can't look around you and find a replacement for the penny as a currency.
Very big change in cost, considering the actual price of the TSA app.