Final Cut Pro X and Lightroom can be controlled by keyboard shortcuts and these can be made to work with a control surface or device such as a ShuttlePRO. But if you don't want to spend money on a hardware device because you think your Magic Trackpad or iPad could handle the same sort of commands as a control surface would, The Touch will appeal to you.
The Touch is a dedicated app to mimic a control surface using your Magic Trackpad or an iPad. The app doesn't work with any other software than Final Cut Pro X and Adobe Lightroom, so it's highly dedicated. Some will say it's limited, but then again, so are hardware-based control surfaces and they cost a lot more than The Touch's 20 or so Euros.
The Touch is well designed. It doesn't take up memory space as a system extension, but once you launch it, it sits in the menubar, quietly and patiently waiting until you hit and hold down the keys that will activate it. If you have trouble remembering which sort of swipe does what, there are plenty of help screens that show you how to do things.
The workflow is approximately like this: you hold down two keys and use your free hand to swipe, tap and do all the stuff you're used to with the Magic Trackpad. Instead of the system-based actions, you'll scrub the timeline, add markers, or insert/overwrite clips.
I tested The Touch with Final Cut Pro X only, as I lack Lightroom. Those times that I could make it work, it worked brilliantly. But I couldn't make it work all the time. For example, you need to switch between modes to perform different tasks. If you want to play the timeline, that's the default startup mode, so you're fine.
If you want to colour grade, you'll need to switch modes and that's where — for me — the problems started. Changing modes requires you to tap the trackpad with more than two fingers and that's where I got stuck.
With every trackpad-type device I use, I run into trouble with multiple finger taps and swipes. I have problems with the Magic Trackpad as well as with Wacom's Intuos 5 Touch graphics tablet that I purchased just weeks ago. I don't know if it's my skin that's causing the problem or the way I put my fingers on the device, but the fact remains that I often need to repeat an action several times before the actual command "gets through".
This makes any software that depends on a touch surface for its efficiency and effectivity utterly inefficient for me. The Touch depends on the touch surface of the Magic Trackpad to work its magic. That makes it unusable for me.
However, if you can work with a touch surface — as I feel many people can — The Touch is a viable alternative to a more expensive hardware device. Unless you want to control all of Final Cut Pro X with non-keyboard controls. In that case, a ShuttlePRO v2 is vastly superior as you can chain multiple settings into one device.