If you know about iphone the siri fasicinates the feature of iphone now google has launched a application named google assistant which is an update of ok google which was present in earlier android phone. The new feature that will attract you are offline commands like play music and more interesting commands like roll a dice, toss a coin will be a real fun and it more over answers all type of questions and also stores it there are many other apps which function more than this but you can always trust google as it update its resources very soon