YAGS is free to download, and always will be. There are many options for you to pick up the game, many of which also support donations for goodies.
itch.io supports Windows, Mac, and Linux. It also supports Android devices via sideloading.
You can also donate here for various extras, such as the soundtrack, wallpapers, and behind-the-scenes book, or even physical goodies like stickers and cards. Donations on itch.io go to the developer (me) and support future game development.
Steam supports Windows, Mac, and Linux.
You can also donate here for digital extras, such as the soundtrack, wallpapers, and behind-the-scenes book. Donations go to Project Ensō and support porting of other queer games.
Google Play (obviously) supports Android devices.