The applications lens is the first lens after the dash home in the lens bar. The applications lens gives you easy access to your apps or apps available for install.
You can use Super+A to open the dash directly at the applications lens.
Right click on a search result to open a preview. The preview shows a short description of the app, a screenshot, its Software Center rating, and what version is available.
For installed apps, you can see when the app was installed and either launch the app or uninstall it. Certain essential apps cannot be uninstalled from the preview.
For apps that haven't been installed, you can install them right from the preview.
Click Filter results if you'd like to only see results for a certain type of application. You can also click Sources ▸ Local Apps to only view installed apps or Sources ▸ Software Center to only show apps available for install.