"I seem to of skipped the additional stats you get from the first few. Neet gives Mystery, Arsonist gives Intelligence, Lighter gives Utility, Fire gives Intelligence, Molotov Cocktail gives Utility, and Lava gives Defense. So the next are just Smelter, Forge, Flamethrower, and Bonfire."
"Smelters are used to smelt things down to use in crafting. Its skill is 'Infinite Smelter: Purify'. This smelts down a target to its most purest form. I assume it can still work on targets that aren't metal. The additional stat it gives is Utility."
"Forges are used to forge things, it says so in the name. Its skill is 'Infinite Forge: Perfect Craft'. Basically it makes it when you use this forge, no matter how many mistakes you make, it doesn't effect the thing you are crafting in the forge. That sounds overpowered, I wonder how long it lasts. The additional stat it gives is Utility."