doors&door explorer subscription ($5.99/mo, 30 days free) unlocks your Knockers list, arrival highlights showing which friends knocked the same door that day, and shared mystery doors: same hidden destination assigned to two people, navigated separately, neither knowing where they're headed until the fog lifts at the same secret place.
For shared doors, Claude goes deeper: reading both users' history of doors, moods, location, and patterns to find the one experience that belongs to both of you. Not a compromise. A match.