Threatbars for you and your pet, with display of time until you pull aggro. The tank and your current threat per second gets extrapolated to calculate when you will pull aggro, so it might be off during burst damage.
Adjust the warning percentage and the time until aggro threshold in the custom options.
Updated version from https://wago.io/NLLPDN2pO, now without library dependecies using the blizzard threat api.