Friend of the show -and one of the finest gentlemen we know- Mark Allison chats with us about Constraint Layouts, what they are, why you need them, what to watch out for and how you can start using them in your application.
Styling Android - Mark's blog [stylingandroid.com]
Marks' Constraint Layout Series: [stylingandroid.com]
Introducing Constraint Layout [tools.android.com]
ADB episode-50 [androidbackstage.blogspot.com]