Reps has a drawing pad on every card, which makes it useful for a specific job: producing a character by hand rather than recognising it in a list.
Reps is built for the written half of a language: characters, vocabulary and grammar you produce rather than hear.
Seeing 憂鬱 and knowing it means melancholy is recognition. Being handed the meaning and producing both characters, correct strokes, correct order, is production. The second is much harder and the first does almost nothing to build it.
Most flashcard apps can only test recognition, because typing an answer bypasses the motor memory entirely. A blank pad does not let you off. Either the strokes come out or they do not.
Supported Apple Pencil models vary thickness with pressure, which makes stroke weight visible in a way a uniform line does not.
You compare what you drew against the model on the back of the card and rate yourself, the same as any other card. Judging your own attempt against the reference is itself a second pass over the material, and it is where you notice the stroke you always get wrong.
A class per language, subjects by level or by source. Japanese holds N4 Kanji, N3 Kanji, Verbs. Chinese holds HSK 3, HSK 4.
Cards cannot be moved between subjects later.
Both card normally as text. Reps handles any script your device does. The drawing pad is an addition for the characters themselves, not a replacement for ordinary vocab cards.
No. Reps covers the written side of a language: producing characters, vocabulary and grammar from memory.
You check it, against the reference on the back of the card.
Yes. Reps uses your device's keyboards and supports any script your device does.
For writing practice, effectively yes. A finger works but is imprecise for anything with many strokes.