This a bit of a long shot but a long time ago I saw a website/web app (It may have been green coloured but could be wrong) that was a database for verbs and how they were used with other other words. So for example, 開ける would it give you a list of all the most common nouns that are used with this verb. So it might show
ドアを開ける
etc etc…
It might not have been just for verbs but for relationships between words sorted by frequency they are likely to appear. I’ve had a good look but can’t find it anywhere, anyone got any ideas what it might be?