We are working with SmartThings to get a public version of the SharpTools companion SmartApp published, but they have quite a backlog at the moment and indicated that it may take several weeks to get the SmartApp published.
In the mean-time, we decided to share the SmartApp code so other users could start Alpha/Beta testing the SharpTools Android app and providing feedback. As an added upside of this approach, we can receive feedback from users about the SmartApp and can make adjustments to it during the alpha/beta testing.
Once the SmartThings team has published the companion SmartApp, it should make the authentication flow much easier. With a published SmartApp, users will be able to simply click the Authorize/Authenticate button from SharpTools and once they have logged-in, SmartThings will take care of installing the public SmartApp.