Calca

Symbolic calculator

Reviews
Discussion
If you like Soulver (http://www.producthunt.co/posts/864), you'll love Calca
Tydlig (http://tydligapp.com - The calculator reimagined for iOS 7) also got a lot of love a while back here - http://www.producthunt.co/posts/275
these kind of text editors are awesome, just wish they would allow for importing of external data