When your destination airfield name appears at the top of the screen (whether this be on ipad or GPS device) in the text format:
DEST: <airfield_name>
Just tap/touch the screen over the DEST: part of the text and the approcah plate will pop up.
This is easier and quicker (in flight) than holding your finger over the actual airfield position on the chart for a few second and waiting for the menu to appear and then selecting the 'airfield name' then 'approach info' form the menus.
doing it by using the text at the top of the screen is a one touch way to acces the airfield plate for your destination.