MattOOC displays on-screen reminders when you're missing important buffs or don't have your pet summoned.
Track any buff or pet by name or spell ID, customize colors and effects, position each reminder independently, and save different setups per character.
Type /mattooc to configure or click the minimap icon.
Caution
Reminders only appear out of combat due to Blzzard addon API restrictions in Midnight. They will also only work before a M+ key has started and not during.
Download it on Curseforge: https://www.curseforge.com/wow/addons/mattooc