This addon allows you to select a wishlist of items from the Blizzard Encounter Journal loot tables. Then once in a raid it will prompt you to switch specs if the boss only drops items from the other spec.
eg: For Horridon you mark 2 dps items (for off spec) but no healer items (your main spec) as you have got them all. When you get to Horridon the addon will notice your Loot Specialisation is still healer but you have no healer items in your wishlist. It then sees you DO have dps items in your wishlist from that boss so it suggests you change loot spec.
Initially the addon allows you to mark a wish list. This is working so far. I will shortly add features to detect which boss you are on and display a warning about spec. I then plan to add a button to allow you to click to change to accept the warning and change spec.
Hopefully with this addon you will never be in the wrong loot spec again.