The Irish IAA VFR chart isn't available digitally. If you want it on a GPS system, you'll have to scan it in yourself, and calibrate it.
You might find a system that allows you to use the Jeppesen VFR GPS charts with it, but I don't think many people use them on paper in Ireland, compared to the IAA charts.
I use PocketFMS (I'm part of the Beta Crew there) and their charts are all fully up to date for Ireland (and elsewhere).
You can get a free unlimited 30 day trial on the website.
The PocketFMS Foundation.
Where are you based? I fly out of Weston, and would be happy to show you the system sometime if you are around.
dp