Downloading GSplus 0.14 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available. The actual developer of this free Mac application is Dagen Brock. The software relates to System Tools. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe.
From the developer:
GSplus is an Apple IIgs emulator. It's an open-source project based on the KEGS and GSPort emulators. It supports fullscreen, joysticks and audio through the SDL2 library across platforms. The goals of this project are to make an easy-to-install and easy-to-use emulator and to modernize the overall codebase and emulation platform.
You may want to check out more Mac applications, such as BeebEm3, 8Bitdo XPad or Deskcap3, which might be similar to GSplus.