There are many ways in which open data can be used. One example is set by OpenUp (formerly Code For South Africa). Since 2014 they are using open data to manage an app (MPRApp) which allows patients to compare medicine prices.
By checking this data, patients can make sure they are not overcharged by their pharmacies. In practice we are even seeing doctors using the information provided by MPRApp to save their patients money.
There are many ways in which open data can be used.
Check out the full report here.