I use DuoCards for flash cards. The word games are FOCLACH (basically wordle in Irish), litreach (guess words from people saying them in 3 Irish dialects) and seafóid (basically Waffle in Irish). The games are all browser based apps so not in app stores, but DuoCards is.
ETA while DuoCards has built in flash cards, I usually make my own based on the words I learn from all the other sources, and get the translation and grammar details from teanglann.ie, tearma.ie, or nualeargais.ie
*how do you own colossal order, colossal order