I'm not sure what part of Waterford you'll be in, but if you want to work in a combined food and drink destination then you could do worse than hit either The Cliff House hotel in Ardmore or The Tannery in Dungarvan. Both have a range of craft bottles in stock and the Cliff House has always had a Dungarvan cask ale on also. In eating terms, either place serves up some of the best dishes you'll get in the country.
If you're coming soon then you probably won't get the weather, but sitting out on the open decking at the back of the Cliff House's bar, looking out over Ardmore bay, is something special, IMO.
In Dublin you're spoilt for choice, really, and, as mentioned, the Beoir app could be your guide for the most part.
If it were me, I would suggest doing a walking tour of sorts. Beginning at Christchurch (you could see the Cathedral first), have a drink or two in the Bull & Castle, which has amongst the best selection of rotating taps in the city. Then walk down Dame Street, towards Trinity College. If the mood grabs you then head left down Parliment Street for a drink in the Porterhouse Temple Bar, one of the lynchpins of the craft renaissance in Dublin. You could continue through Temple Bar, stopping into Farrington's, which has developed an excellent selection of craft on tap this past year. Then push on through Temple Bar square to The Palace, a truly old-school Dublin boozer, where you could finish with a pint of cask ale and a glass of their own whiskey.
For me personally, if you want more than that, then the other notable destinations are the Cottage Group's pubs in the centre of town: You could be at either Against The Grain on Wexford Street, The Brew Dock on Amiens St. or The Black Sheep from Temple Bar in probably 10 minutes brisk walk. Hard to hit all three in the same evening, however, given their locations.
Personally, for a visitor, I'd suggest Against The Grain over the other two: It's in an area with a little more to offer nearby, both in terms of food and more pubs stocking craft beer.
I guess an alternative route would be to begin in Against The Grain, walk down Angier Street towards the city centre, stopping for a pint in The Long Hall (another venerable old Dublin pub) and then into Temple bar, doing The Palace, Farrington's, The Porterhouse and The Bull & Castle in that order.
