GUI editor

For Spark, is it possible to edit the user interface with a visual editing tool, or is there a preferred one? Some things I have been able to edit after some searching (such as the help dropdown in the main window), but others such as the ‘Accounts’ label on the login screen are seemingly untouchable despite my efforts. Being able to load an editor and click on the label and go from there would be a great help.

I am using Eclipse. Spark compiles properly (running via the startup bash file rather than compiling to exe for now).

There is no such editor. If you want to edit just labels, then search for spark.i18n.properties file in the source and edit it.