GCSE german vocab learning

at the moment,
im using an app similar to anki to learn a set amount of words each day.
what do you think would be the maximum amount of words i could learn per day with it still being effective?
im thinking 5-7 but i started using this app quite recently and i wont have time to finish learning each bit of vocab before GCSE season
if you learnt vocab this way how many cards did you learn a day and was this effective for u