Comment by nativeit

ServerCat is very similar to this, for a GUI option. If you need features suitable to a more diverse and/or complex setup, Devolutions’ Remote Desktop Manager offers a fairly full-featured free version of their enterprise-grade software.

The former is OSS, and I’m not sure how active its development is at this point, although it’s available in the App Store for desktop and mobile. RDM is proprietary, and also offers a mobile app.