It depends. When new Neon is launched your apps will need to be updated and in many cases that will happen automatically. You may be prompted to log in again in which case, if you are both a Neon and Lightbox subscriber please use your registered Neon email address.
In general we would expect phones and tablets to update automatically.
Some TV's will prompt you to update the app but if you do not get an update prompt then you will need to manually update the app.