Create Apps for SharePoint by using Visual Studio
Apps for SharePoint have a smaller footprint than other SharePoint solutions because they aren't installed on the host server, so they don't overload a SharePoint site with API calls. Instead, you can use different hosting options to manage those services independent of the app package that you add to your SharePoint site. You can also create apps for SharePoint online by using the "Napa" Office 365 Development Tools. For more information, see SharePoint 2013 and Build apps for SharePoint.
To get started, you set up and configure a development environment on either a local computer or Office 365. You also download and install the Office Developer Tools for Visual Studio and SharePoint Client Components, which provide the project templates and other files that you need. For more information, see Get started developing apps for SharePoint.
When you create an app for SharePoint by using the App for SharePoint project template, a wizard asks you to choose settings for the app, such a location for the app and how you want to host it. Visual Studio generates a solution that contains all of the necessary files to start to test your app for SharePoint. For examples, see “Basic tasks and samples to show you how to create a SharePoint-hosted app, a provider-hosted app, and an autohosted app” in Get started developing apps for SharePoint.
You can create a more full-featured app by adding other SharePoint project items, such as client web parts, lists, content types, content types for external data sources, and workflows. For more information, see Creating apps for SharePoint and project items from templates.
In addition to using Visual Studio, you can also create these apps by using the "Napa" Office 365 Development Tools. By using this browser-based authoring tool, you can develop not only apps for SharePoint but also apps for Office. You can, for example, create your first few solutions by using the "Napa" Office 365 Development Tools and then download and open those solutions in Visual Studio if you later decide you want more development features and support. For more information, see Sign up for an Office 365 Developer Site.
You can integrate data that’s stored in SharePoint, such as list information or documents, into Office by using an app for Office. Moreover, the package of an app for SharePoint can include an app for Office package. When users install the app for SharePoint, the app for Office is added to a corporate catalog in SharePoint. For more information, see Overview of apps for Office.
When you’re ready to publish your app for SharePoint, you choose a few settings in the publish wizard. Visual Studio generates all of the files that you need to publish the app to the SharePoint corporate catalog, the Office Store, a shared network folder, or an Exchange catalog. For more information, see How to: Package apps for SharePoint for publishing by using Visual Studio.
If you get stuck or have questions about how to develop an app for SharePoint, you can read and post queries on the SharePoint 2013 for Developers forum.