Microsoft recently announced that they are launching a virutal assistance called cortana application for iOS and Android devices. Cortana got popularity from Windows 10, before that cortana is mostly used in windows mobiles and devices for virtual assistance.
If you are windows phone user or windows 10 user then you will feel the importance of cortana virtual assitance. It will really helpful because it is an artificial intelligence character. You can use virtual assistance for your any work and even you can ask questions.
Microsoft will provide notification support for these both. You will only get notification of your work.
The most important thing is Microsoft's Cortana will use Bing search engine and data stored on the user's smartphone by to make personalized recommendations. You will get result from bing search which is already a biggest search engine.