I've started using deck builder for more than just my own decks, but also to store other popular decks by format. It helps me study and prepare for competitive play and has the benefit of offline cache for pictures and rulings etc (compared to just viewing the deck list on a site like MTGGoldfish)
Being able to "install" or "auto-populate" these popular decks would be very handy indeed!
If you can find the decklist in the appropriate section: hit view in deck builder and a copy should end up in your database
Do you mean, if I can find the deck list on a website? Not sure I'm following?
If you can find the deck listed on the deck forums, you can use the app to export a decklist from the forums to your deck builder