CurrencyFreaks is described as 'Currency Conversion API and Forex Exchange Rate data' and is an website. There are 2 alternatives to CurrencyFreaks, not only websites but also apps for Self-Hosted. The best CurrencyFreaks alternative is Exchange-RateAPI, which is free.
Exchange-RateAPI is a real-time currency exchange rate API for developers, providing live and historical rates for 160+ currencies sourced from Reuters/Refinitiv and interbank feeds, updated continuously.
Free, hourly-updated exchange rates and currency data - a simple, accurate, easy-to-integrate JSON API with great documentation. Free for personal use, a bargain for everybody else.
United Kingdom