We are currently in the process of revamping our mobile app experience and because of this, Practice does not currently have a mobile app available for download.
If you previously had the app - it may still be available on your phone, but new downloads are not possible.
We don't currently have a timeline for this, but a great workaround is to use the mobile web version of our app. There are many ways you can favorite the web page and save it to your home screen for an app-like feel.