do those exist anywhere?
There’s decks for anki, just search hiragana on ankiweb.
Personally I found flash cards a bit slow for hiragana and katakana, and used the tofugu quiz: https://kana-quiz.tofugu.com/
i should have specified that i was hoping for mnemonic based approaches
Renshuu would be my recommendation. The mnemonic system there is mostly community based, but I reckon that makes them extra memorable.
I bought and wrote out physical flashcards for hiragana and katakana
I’ll probably still have them somewhere
Tofugu uses mnemonics.
Their quiz isn’t flashcard based, but it’s close enough imo.
I really like the flash cards from the Tuttle Hiragana/Katakana book. They have cute pictures and phrases to help remember the kana. They are physical ones meant to be printed out. Japanese Hiragana & Katakana for Beginners
They are available from Tuttle on the website without buying the book. Direct link to the cards (this link can be found on Tuttle’s page): Dropbox

