How can make sure my app will run well on GDR3 and 1080p windows phone devices?

How can make sure my app will run well on GDR3 and 1080p windows phone
devices?

We are planning support the next generation of devices with 1080p
capability. However since this is a new aspect ratio, we would like to
make sure that our apps will run well on the new devices.
Moreover, this new resolution will be supported on GDR3 for WP8, so we
also would like to make sure our app will run on it without any issue.
Do you know how can check our windows phone application on GDR3 or 1080p?
Herb