Note 1: By default this feature is enabled in “Developer Site”. So if your site has been created with the “Developer Site” template then do not use this article since this is for non-developer sites.
Note 2: Enabling this feature is not recommended for production sites. Sideloading apps is insecure. The main reason for blocking sideloading by default on non-developer sites is the risk that faulty apps pose to their host web/host site collection. Apps have the potential to destroy data and make sites or, given enough permissions, can even make site collections unusable. Therefore, apps should only be sideloaded in dev/test environments and never in production.
(Referenece: Apps for Office and SharePoint blog)
Pre-requisites
- Install Windows PowerShell from Windows Management Framework (I installed the Windows Management Framework 3.0).
- Then install “SharePoint Online Management Shell” Link.
Procedure