Once upon a time, when I had to top-up my phone with airtime in a public vehicle(trotro), I didn't have any coin on me to scratch so I had to scratch it on the side of the bus. After having to scratch it, unfortunately for me, when I entered the digits, I was alerted that the card had been used already because the digit had been copied from me in the bus.
What Inspired me? The pain and stress I had to go through just to load my airtime.
Who is your Target user? All smart phone users.
What key feature I'm I most proud of? Its smartness in quick way of loading airtime.