Another alternative is Postman [0]. Supports C, Java, Go, Ruby, Swift, etc. Available as a Chrome app. Not really the same (doesn't convert from one to another AFAIK), but it gives you a common interface.
Thanks for the mention. Postman can import curl commands too and then of course convert to all these languages. We are opening this up so that converters can be added/coded dynamically.
[0]: https://www.getpostman.com