Snowflake is described as 'brand-new zero-config emulator frontend powered by HTML5. Ready to use out-of-the-box '. There are five alternatives to Snowflake for a variety of platforms, including Mac, Windows, Linux, Xbox and Android. The best alternative is RetroArch, which is both free and Open Source. Other great apps like Snowflake are OpenEmu (Free, Open Source), Nostlan (Free, Open Source), RetriX (Free, Open Source) and RetroX (Freemium).
What is RetroArch? RetroArch is a modular multi-system emulator system that is designed to be fast, lightweight, and portable. It has features lacking in some emulators frontends, such as real-time rewinding and game-aware shading. What systems does it play?
Open Emu is an open source project to bring game emulation to OS X as a first class citizen, leveraging modern OS X technologies such as Cocoa, Core Animation and Quartz, and 3rd party libraries like Sparkle for auto-updating.
A front-end or user interface (UI) is the presentation and interaction layer of an app or website. Most modern emulator apps have basic game list UIs that you can interact with using a mouse/keyboard but not a game controller.
RetriX is an emulator front end for UWP, on all the hardware platforms it supports: it serves the same purpose as RetroArch but is built from the ground up to integrate as well as possible with Windows.