Nintendo DS and 3DS storage devices are used to store a licensed developer's work-in-progress images, homebrew video games, and downloaded commercial games (since the Nintendo DS is not sold with a rewritable storage medium). Licensed developers, however, can use a blue Intelligent Systems Nitro Emulator box to flash cards. These devices are also known as "flashcarts" or "flashcards". There are two main classes of flashcarts: older devices which fit in Slot-2 (the Game Boy Advance Game Pak slot) and newer devices that fit in Slot-1 (the DS Game Card slot). Slot-2 (or first-generation) devices have been historically cheaper due to economies of scale (inherited from their use with Game Boy Advance), but require a booting tool in Slot-1 in order to use the touch screen and other DS features.