Filter against /Developer rather than against /Applications. This enables support for Xcodes that aren't in /Applications.  You can't pick such an Xcode yet, but if you set the path to its /Developer by force, it now works.
Default to the Xcode preferred by xcode-select rather than /Developer.
Enable selecting an Xcode.app in the /Developer-selection panel. AppKiDo will now automatically translate such a selection to the bundle's Contents/Developer directory.
Don't disable the path selection controls under any circumstance anymore. Further enables selecting any Xcode.
Removed the “/Developer or not /Developer?” matrixes and changed wording and size to reflect that the path selection is now the only way to choose an Xcode.
Added ALSimpleTask to the project.
Tweaked the ALSimpleTask API, filled in missing lines in dealloc (I brought the class over from a project using ARC).
Edited comments.
Overhauled using what I now know about xcode-select.
Got rid of needless "elasticity" in the About box.
OCD. Moved protocol method from the "Private methods" section to its own section.
Removed stuff no longer needed after Peter's changes.
Modified devToolsPathFromPossibleXcodePath: to handle a couple of additional cases.
Renamed devToolsPathAccordingToXcodeSelect to pathReturnedByXcodeSelect, and moved some of its logic into AKPrefUtils.
Removed needless imports, edited comments.
#9. Pulled @boredzo's changes for allowing Xcode.app to be anywhere, not just in /Applications. Changed how the Dev Tools prefs UI works. Now you always select your desired Xcode.app, regardless of whether the Dev Tools installation is "old-style" or uses a standalone Xcode.

Moved devToolsPathFromPossibleXcodePath: to AKDevToolsUtils so that AKPrefUtils wouldn't have a dependency on AKDevTools.
Removed an NSLog.
#9. Modified the prefs UI to reflect that you now always select where Xcode is.
Made short labels unselectable.
Removed commented-out lines.