According to Google, “We use apps to call friends, send messages or listen to music. But sometimes, it’s hard to find exactly what you’re looking for. Today, we’re introducing a new way for you to search for information in your apps on your Android phone. With this new search mode, called In Apps, you can quickly find content from installed apps.”
Basically by searching under the “In Apps” tab in the search bar on your Android phone, instead of trying to search the web, it will search within your apps itself. This will be ideal if you’re trying to bring up a particular message, or if you have saved a document and you’re unsure if you saved it in Evernote, Google Drive, Dropbox, in your email, and so on.
However according to Google, not all apps will have access to the feature yet. For now only Gmail, Spotify, and YouTube will support it, but Google will add more apps in the future such as Facebook Messenger, LinkedIn, Evernote, Glide, Todoist and Google Keep, and we presume more will keep being added in the future.