Ring by Voice for Android
To provide properly works of application on the smarphone must be installed Google Search app, but most of phones have this app installed by default so probably You mustn't install it.
After you speak a numbet to some person or contact and after correct or incorrect call, You will see resultat of Your speech to check whether app recognize Your words properly.
Very practical solution is widget, which you can place on some of Your smartphone's screen and if You want to call someone, all You need to do is only click it and say number or contact!
Nices
by Z####:
This is unmatchable