This short article shows how to resolve the error “Sideloading of apps is not enabled on this site”.
When you can Start to run in your App for SharePoint then you might get the error “Sideloading of apps is not enabled on this site”.
You will find few links for this solution but some of them when you copy and paste the code into your notepad then it becomes a nightmare. The one that copy and paste and will run straightaway is this one http://www.superedge.net/2014/03/sideloading-of-apps-not-enabled-on-this.html.
After run the PowerShell Script you should be able to run your app.