Autohosted Apps was a preview program to determine how best to provide a seamless deployment experience for creating apps for SharePoint. Back in May, Microsoft notified that this program would end on June 16, 2014 and developers would not be able to create new autohosted apps in SharePoint. Since developers can no longer install autohosted apps in SharePoint Online, the capability to create autohosted apps and deploy them into the production SharePoint Online site has been removed from the Office Developer Tools in the Visual Studio 2013 update 3, released August 4,2014. If you have already hosted some apps, it will work as it as until Microsoft notifies about it again.
If you are currently using autohosted preview apps in a production environment, we recommend that you follow this step-by-step MSDN article on how to transition autohosted preview apps to provider-hosted apps, the new model we’re improving. If you want to just pull the data from your app, please contact the relevant Office support resource for assistance.
Read more about it here.