A free program for Android, by Blaze Labs.

Voice Search is a useful tool that will help you search through a variety of things such as contacts, messages, photos, videos, and more using your voice. This tool is easy to use as you don’t need to type and it also works offline. It uses speech recognition to convert voice into text which is then used for searching. This helps in finding the correct results as it understands the words you are using. This tool is also available on iOS and Android devices. 

The app is very easy to use as you can simply say, “Search for X,” where X can be anything and it will search for that.