When you use a minibus taxi as a mode of public transport in South Africa, you are familiar with the scenario of taxi mathematics gone wrong when the taxi fare of all passengers just doesn't add up and brings out the horns of the taxi driver. The idea is that the money travels from the back seat to the front seat. Should the total not add up, the taxi driver will park by the roadside and let all the passengers resolve this impasse. The FrontSeat calculator is a mobile app that will assist in calculating the money in a taxi.