in Byn is a free currency converter app developed by Dadatak for Android 9.0 and above. The app is designed to help users convert Belarusian rubles into other currencies and vice versa, making it a useful tool for those who frequently travel or do business across borders. The app also offers a fuel cost calculator and cryptocurrency converter.

The app's Converter tab allows users to quickly find the equivalent of money in both new and old currencies. The Purchase tab helps users calculate change in stores, taking into account both old and new currencies. Lastly, the Exchange tab helps users convert rubles into any currency at the NBRB rate or the best rates of banks.

Overall, in Byn is a simple and straightforward currency converter app that can be a useful tool for travelers and businesspeople alike.