Hi Ernie, firstly I absolutely love your flashcards app for my mandarin; the simplicity yet power of it, uploading from excel, supporting a developer with a personal mission. All great, which is why I donated to your site today.
An improvement in my view would be shifting to ‘buymeacoffee.com’, see eg shortnordic.com for an example. This Is more user friendly, allows multiple payment methods incl Apple Pay (which will thus lead to more donations) and allows a personal message! (Which I think is very sensible with a donation) “!!”