So I have been working with SP2016 Beta 2 and one of the complaints right now is that the Visual Studio 2015 Office Developer Tools Preview SharePoint Hosted Add-In will not deploy. So basically you need to change the target office version to 16.0 in the Visual Studio project file. The steps are illustrated below.
Create a new project:
Make sure to choose SharePoint Online as the target:
Choose SharePoint Hosted Add-In:
Now when you try to deploy you will get this error:
Open up the project file and change the target office version to 16.0
Deploy that SharePoint hosted Add-In to SharePoint 2016 Beta 2!
So after you change the target office version to 16.0 you will now be able to deploy to SharePoint 2016. Microsoft is currently working on fixing this in next phase of Visual Studio 2015 Office Developer Tools. In the meantime start digging in.