but wow, this is very eerie—i have not written an app but thought about it!
i am using a combination of three iOS applications right now to achieve what both these apps are offering. the built-in dictionary of course, notes, and reminders. after looking up words using the built-in dictionary, i put them in notes. then about once a week, i do a review and set reminders for a few select words.
i have been doing this for a few years now. it's heartwarming to see these ideas validated not in one but two applications.