Press 'Space' to generate a pack. Press 'X' to view the pack as a whole and the previous pack. I made this program so that I could turn my bulk cards into draftable packs of 15 cards to play with friends. I sorted my cards by color and rarity, with multicolor and colorless cards being counted as their own color I like putting 2 lands in each pack, so players can have an easier time color fixing to play on curve. I keep my bulk mythics and specials in with the rares, so they would be counted as part of the rare category.
I am going to update this program to decrease the odds of getting multiple cards of the same color in the Rare and Uncommon slots. Odds: Lands 1/4 Mana fixing or tri land 3/4 guildgate/dual land Everything Else 3/18 Red 3/18 White 3/18 Blue 3/18 Green 3/18 Black 2/18 Colorless 1/18 Multicolor each pack is guaranteed to have one common of each color