I don't have any suggestions. I can't think of any proprietary app good enough that I'd give up control of my computing for. However, consider objective requirements rather than subjective terms like good. What do you use the proprietary app for, why are existing free alternatives not sufficient, and can a free app be made that satisfies those requirements?

It’s not an Android app but ServerCat is the best multi device monitoring/ssh software for mobile that I’ve come across. Sadly none of the alternatives on iOS or Android compare. Totally room for a proper competitor that fits a lot of information in an intuitive and clean ui.

AnyType , AppFlowy, Affine - alternatives to notion LibreSpeed - alternative to Speedtest.net And Penpot - alternative to Figma