Set custom DPI for different apps? I own a rooted Nexus 7 16GB running on 4.2.1. The default interface (stock ROM) is the phone UI. I have read mods and a certain app that changes the DPI to enable the tablet UI.

I would like to have the phone UI primarily but I want certain apps to run in the tablet UI mode. Is this possible? If so, how?
Maybe you should look into this ROM, however I cannot guarantee if there is an availability for the Nexus 7. 

To quote:


This rom lets you scale and project every app, every widget, even
systemcomponents individually.
Remember, android is modular, everything is an app: Lockscreen,
navigationbar, dialogs, popups, keyboards, widgets, and your regular
apps of course.
Apps have the capability to switch into various designs or layouts
according to the device they run on.


It is hybrid, meaning, that individual apps can change from tablet mode to phone layout mode on the fly. It is open sourced and is available on github.

Edit: 

Thanks to eldarerathis for supplying the linky to the N7 Version found on XDA.