Excellent app!
Fingers crossed that the dark theme might be released.

This app offers a suite of specialized calculators, including scientific, financial, programmer, and basic functions. It also features a currency converter and a comprehensive unit converter for various needs.
1.10
March 21, 2020
• We’ve added support for dark mode on iOS 13.
$1.99
Calculator² Premium
Unlock the Financial Calculator and Currency Converter.
Calculator² provides a Scientific Calculator, Financial Calculator, Programmer Calculator, and a Basic Calculator. It also includes a Currency Converter and a Unit Converter.
The Currency Converter in Calculator² offers accurate conversions between over 150 world currencies. Exchange rates are updated to real-time values using the Open Exchange Rates API, and favorite conversions can be saved.
Calculator² is free to download and use for its basic functions. However, the Financial Calculator and Currency Converter features are unlocked via an in-app purchase.
Calculator² is designed for iOS devices, specifically supporting iPhone and iPod.
The app was last updated on March 21, 2020, to version 1.10. Update frequency can vary based on developer plans and user feedback.
Calculator² has an age rating of 4+, making it suitable for a wide range of users.
While the description doesn't explicitly state offline functionality for all features, core calculator functions and unit conversions are typically available offline. Real-time currency conversion may require an internet connection.
The provided description does not mention the ability to export calculations. The app focuses on providing calculation tools and conversions.