BANKS DO NOT SIT AND SPY ON ITS CLIENTS ALL DAY LONG.
As long as you pay your debts and not commit fraud, then you are fine. However, if you default on your debt or lie on a loan application and you start running away, that is when this app will become useful to the bank. Not only to pinpoint your exact location when their fraud investigators go with the police to arrest you, but also get the Sheriff that much needed address to serve court orders.
This has the potential to save banks millions of Rands spent on debt collectors, getting court orders every time a client moves away when they need to serve documents, and millions more in administrative costs. Don't, for one moment, think they will not use this information - gathered legally by their app from your mobile phone - when needed.