I think the ruling makes it clear that Uber has a huge amount of control over the driver, how they do their job and how many fares they take (with penalties). Since Uber is interviewing the drivers and requiring that that driver show up for the fare, it's not clear that a driver can substitute someone else for their fare). You can argue that there is an obligation on the specific driver to complete fares for Uber and the driver depends on Uber to supply fares. The ruling makes sense that they are employees as UK law defines the term.
I don't think you can argue that an App Store developer is a disguised employee in the same way, Apple/Google have very little control over how I write my app, they don't care if I write it or I subcontract and I don't think Apple have any expectation that I will write the app.
Uber could never call itself a "marketplace" for drivers. It operates much more like a driver agency.
Edit: there are genuine online booking agencies for drivers in London, like http://www.kabbee.com, which act as a front-end for independent minicab drivers. I think this is much more that way it should operate if the drivers weren't employees, as Uber argues.
* "controls the key information (in particular the passenger’s surname, contact details and intended destination) and excludes the driver from it"
* "determines issues about rebates, sometimes without even involving the driver whose remuneration is liable to be affected"
* "handles complaints by passengers, including complaints about the driver"
* "subjects drivers through the rating system to what amounts to a performance management/disciplinary procedure"