Pokémon Attack Power Calculator
This program IS one of my favorites. There are only a few very minor errors in the formula. Otherwise, this fits exactly with the Ruby/Sapphire/Emerald formula. It supports level, attack type, defense types (2-type), attack power, attacker's Attack/Sp. Attack stat, defense's Defense/Sp. Defense stat, hold item bonus, critical hit, low HP Trait bonus, Ability bonus (both offense and defense), move same type as user, weather, Nature bonus (both offense and defense), random number, number of times move hit the opponent, and opponent's HP.