These recipes will give you "Spawner Builder" item. When you use this item, it will create a spawner with the specific monster inside. This spawner is the usual, in-game, nothing new.
Once you build your spawners and you have no more Spawner Builders, you can freely remove this mod.
On the crafting table: Moss stone in the corners, iron ingots for the sides.
(M being moss stone, R iron ingot)
The middle item determines spawner type.
Raw Porkchop - pig
Skin - cow
Egg - chicken
Wool - sheep
Arrow - skeleton
String - spider
Feather - zombie
Gunpowder - creeper
Ink Sack - squid
Bone - wolf
Slimeball - slime
Cooked Porkchop - zombie pigman
TNT - ghast