I love the mod, it adds lots of well-needed addition to the nether.
For those who are having issues with NEI not showing up or Applecore crashes, it is because of Think Big Core, the Core for Ad Inferos. (This is for 1.7.10).
1. Go to the config for Think Big Core
2. Set "Fix Vanilla Bugs" and "Extra Spawn Eggs" to false
3. Save the config and you are done!
This fixed it for me, after painstakingly disabling hundreds of mods trying to find the cause. Hope this helps, because this answer is no where on the internet when I looked.