AutoTools Change DPI per application

Hello everyone,
i would like to change the DPI for 1 application in order to render a tablet UI on my phone.
I dowloaded and installed Tasker, Autotools (triggered the trial also) and Autotools root add on.
In tasker, i add the application, add an action -> Plugin -> Autotools add on and then in "screen" i put for example 264 dpi.
When i launch the app, the dpi is changing but when i quit the app, the dpi doesn't revert.
Could you help me please ?
Thanks a lot.