I don’t think scramble mode offers sufficient privacy and is a bit confusing for the person who is being shown the app.
All it does is change the currency symbol and replace transaction values. The transaction names aren’t changed so there is virtually no privacy. All that is achieved is it confuses the person viewing and invites questions about why the numbers are nonsensical.
Even if there were better privacy when inside scramble mode, it’s too easy for the viewer to exit back to normal mode and therefore see normal transactions. All you need to do is press the bar at the top of the screen.
Replace scramble mode with a demo mode in which all transactions are made up rather than based on users own transactions. It should use the home currency and meaningful values. Require authentication (i.e. PIN, fingerprint or face recognition) to revert from demo mode to normal mode.