After recording voice tags for my contacts, I found that it had trouble understanding my commands. I was in a quiet room. Unfortunately, it does not listen over a bluetooth connection, only through the speakerphone mic. I would imagine that driving in my car the recognition would be even worse. Another problem was that if it responded with the wrong contact, it would dial that number and had to quickly end the call by pressing End Call. I deleted the app. Wasted $15.
Ed 1 about Voice Dial (speech recognition app)