RetroArch - RetroArch is a frontend for emulators, game engines and media players.
melonDS - A Nintendo DS emulator with support for commercial games.
Level.io - Flexible, intuitive, and secure remote monitoring and management (RMM) software. Control and manage your devices securely, right in your browser, from anywhere in the world. Get started today.
Drastic - Drastic is a Android DS Emulator
RetroFab - Playable 3D simulations of vintage electronic games
No$GBA - If you have no money you can play Nintendo DS and Gameboy Advance game.