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

My experience is that duolingo is a good component of language learning but is bad as a whole package. I have that, a flash card app, daily word games, and a YouTube channel for a children’s TV network in my language. None of them individually would teach me the language, but collectively they reinforce each other and fill in many gaps. Alas, neither innovative language nor lingodeer have the language I want at the moment.

If I understand correctly we can’t do it to anything new because the ratios in the atmosphere got messed up after nuclear weapon testing in the 1950s. Anything breathing after that time can’t be properly compared with this technique. Maybe that will change though.