助数詞を練習 (じょすうしをれんしゅう) – Let’s review Japanese counters! [Archive.org URL]

This is a tool that’s meant to help you study Japanese counters. You’ll be given a random item and a random number, and then you tell us how you’d count that in Japanese. Current study packs include common counters, essential counters, and counters for JLPT N4 and N5.