Freebbble!

(480×800 screen size, vector).

Android Design Grid Template PSD is a free Mockup design resource made by Dribbble user Michael Henning. As far as I can tell, its license is Free for Commercial and Personal Purposes.

Helpful hint: Dribbble users are nice. If the license is unknown, it is usually because they forgot to mention it explicitly; not because they were being stingy. Ask nicely and they will probably allow you to use it.