This is a subclass of UITextField that specifically deals with the entry and formatting of currency.
Open your terminal and run:
git clone firstname.lastname@example.org:iJoeCollins/JOECurrencyTextField.git
Drag the JOECurrencyTextField folder into your project.
Then in your .pch file:
Or just import the header files where needed.
Further details and examples are available in the programming guide.
It is open source and distributed under the MIT License (MIT). That means you have to mention Joseph Collins as the original author of this code and reproduce the LICENSE text inside your app.
You can purchase a Non-Attribution-License for $100 USD, for not having to include the LICENSE text.
I also accept sponsorship for any specific enhancements you may require. Please contact me via email for inquiries.