This article shows how to install the "Napa" Office 365 Development Tools.
Napa is a New Cloud App Model that allows you to build a new class of apps right within Office 365 and SharePoint.
Napa Tools is a nice way to get started building apps for Office or SharePoint directly out of a browser window. All you need is an Office 365 account and a supported browser. To get started, sign up for an Office 365 Developer Site. Apps developed in Napa Tools can be moved to Visual Studio 2013 for adding more features.
Use the following procedure for the installation.
Step 1: To develop apps for SharePoint 2013, you first need to create a developer site. Here I' m adding a new Developer Site named “AppSite”.
Step 2: Go to "Site Contents" of “App Site” and click "add an app".
Step 3: Select “Napa Office 365 Development Tools”.
Step 4: Click "Trust It" when prompted for "Do you trust “Napa” Office 365 Development Tools?".
Step 5: You can see that Napa Tools is now available in your Site Contents page.