Drive-enabled applications can leverage Google Drive to help users create, organize, discover, and share content. You need to integrate your app with the Drive UI to take advantage of these features. You will integrate your app with the Drive Create button, integrate the "open with" contextual menu item, and integrate the Google picker dialog.
Your app can appear along with other apps in the Drive UI, letting users choose to create or open documents with your app.
After users have installed a Drive app and authorized its access to their files, the app is displayed in the Google Drive contextual Open with menu for files of the assigned MIME types. For example, users can select an application from a menu like the following:
Users can open certain file types with a certain Drive app by default, provided that the app has registered the correct MIME type or file extension for default access. For more information, see Define what Drive files your app can open.
The New menu in Google Drive lets users create a new file using any app that is installed and that supports UI integration. To create a new file using an application, a user can just click on the corresponding icon in the New menu as shown:
Custom thumbnails and metadata
While Drive can automatically generate thumbnails and index most popular file formats for search, proprietary formats are covered too. Your app can provide a custom thumbnail and extracted text to index when it creates or saves a file.
For more information, see the file metadata guide.