PolyRoots
PolyRoots finds the roots of a polynomial to any chosen accuracy using Laguerre's Method. The coefficients of the polynomial can be real or complex. PolyRoots uses the multi-precision RR type from Victor Shoup's NTL.
http://www.shoup.net/
PolyRoots is a Universal Cocoa application.
Freeware.
Version 2.0 allows polynomial entry in the form: x^2-4x+3