Developer Daniel Horn has released a runtime based object inspector for Firemonkey in Delphi 10 Seattle. The original version of this code is an Object Debugger created by Marco Cantù for VCL. What this tool allows you to do is embed an object inspector (like you have in the Delphi IDE) into your runtime applications and inspect object properties. This can greatly enhancing your debugging capabilities because you don’t have to redeploy your application or write text out to a console to investigate objects (and change properties). You should be able to compile this into your Android, IOS, OSX, and Windows applications. Apparently there is a mobile demo and a desktop demo because the desktop version has a floating form for the object inspector. The inspector itself is within a TFrame so you can embed it practically anywhere. Full source code is available under an MPL 2.0 license.
Head over and download the runtime object inspector for Firemonkey in Delphi 10 Seattle from Github.