Left4Resi

Left4Resi tells your party which Mythic+ dungeons you still need to time for a Resilient Keystone level.

Type /lr 18 and it posts to party chat:

Left for Resilient 18 (3/8):
Altar of Fangs (+16)
Kings' Rest
The Blinding Vale (+17)

(3/8) is how many dungeons of the season pool are left. (+16) is your best timed key in that dungeon this season; no number means you have not timed it at all.

Commands
/lr 18 - lists the dungeons you have not timed at 18 or higher.
/lr - uses your next Resilient level (your lowest timed level + 1, at least 12).

Good to know
- When you are not in a group, the list is shown only to you.
- During a key or a boss fight the game blocks addons from sending chat, so there it is also shown only to you.
- It counts the current character's season bests, so keys timed on other characters are not included.
- The dungeon list comes from the game, so it follows the pool into new seasons without an update.
- Retail only. No settings, no setup.