The best alternatives to NESBox are Epic Games, Tribe Games, and Afterplay. If these 3 options don't work for you, we've listed a few more alternatives below.
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Afterplay is a browser-based emulation platform. You can play your retro games on any of your devices and continue from where you left off with synced saves. No jailbreak or side loading is required as it is a web app you can add to your home screen.
In Sketchies, the first game in Selfie Games, an app of selfie-infused casual TV party games, 3-10 players start by taking selfies on their phones, which then appear on the TV (Fire TV, Chromecast, Xbox One, web browser..). Then they sketch absurd scenes of their friends, write fake captions for those scenes, and try to guess the original caption.