David updated his mobile phone and he's lost a lot of apps. Leo says that if he opens the Google Play store, there's a menu item for "My Apps." It'll show what's on his phone and what isn't. If he presses and holds the first app he wants, he can then select all the apps he wants and it'll reinstall them.
He's also having trouble his 1Password vault. Leo says that if he lost the password vault, or the password in general, then he may be out of luck as he's responsible for that password vault. He should make sure it exists in more than one place, like DropBox and his desktop computer. If he has the vault, he can sync it back and he'll be good to go. It's important to remember that the user is responsible for it, as 1Password doesn't have it. That keeps it more secure. He can also backup his settings to Google and even Samsung for his Samsung phone.