Video Game and Duck Emulator is an open source project, licensed under the GPL 3.0. Anyone is welcome to contribute improvements to the code. Thanks to many such contributions. VideoGame uses a lot of open source project, the links are as follows
https://github.com/rafaelvcaetano/melonDS-android
https://github.com/dolphin-emu/dolphin
https://github.com/seleuco/MAME4droid-0.139u1-
https://github.com/Swordfish90/Lemuroid
https://github.com/Rakashazi/emu-ex-plus-alpha
https://github.com/mupen64plus-ae/mupen64plus-ae
Video Game can get Rom from third-party website, the link is as follows, Make sure you have the authority to use them.