Publish your application
Click on the "Publish" button in the bottom bar of the editor which will take you to the publish page.
On the page you will see a list of files you have changed and be prompted to write a small summary of the changes you have made. These comments can be especially helpful when working in a team, se everyone can stay up to date.
Once your changes have been published you will be taken back your project page.
Here you can click the link to see your live application, invite new team members, or create a new branch if you wish to make more changes.
You can read more about branches here