I had Drive Kit Plus installed on my 2014 SLK, which is the supporting option needed to connect with this supporting iPhone App. The Kit provides access to Facebook, Google+ & Twitter for those that need that in their car, which is a good safety improvement over texting. The Google Maps (not Apple Maps) implementation is perhaps one of the best and would be great for customers without COMAND (which I have) or Becker Nav.
I must say though, that Drive Kit Plus is a huge disappointment when it comes to usability and integration with the rest of the vehicle. Even I, as someone that has spent 40 years in programming/hardware/support and can generally be technically self-sufficient, have found it difficult to use in almost every way. It must be turned on in one of two not-intuitive ways each time you turn on your vehicle and want to use the capabilities. You must physically plug-in your iPhone to an adapter installed into your glovebox (no wireless) to access any capabilities. There are very significant limitations when Drive Kit Plus is turned-on either completely inhibiting use of standard audio sources such as AM/FM/Sirius/CD (and COMAND Nav), or in the other mode, limiting access to those sources only to volume changes while Drive Kit Plus is active (i.e. no source or channel changes while the kit is active.) I cannot access iPhone music in one mode, despite the manual suggesting it’s possible and the interface looking like it should be playing. Internet streaming radio does work, but not via services like Pandora. The manual is very difficult to comprehend — even the English version describes a “c (with a graphical box around it) delete” button to enable the Kit that does not exist in my US vehicle —after lots of trial-and-error, I found the engineers really meant the “CLR” button next to the Command dial. If you want to access Siri, it’s only available once Drive Kit Plus is started, and you then must take your eyes off the road to move your cursor using the Command dial over a small microphone icon at the top of the display. There is no simple button (or long push) to access it e.g. on the steering wheel as other mfgr Siri Eyes Free implementations use.
I’m very disappointed, as the limitations and more complete implementation of this App with Drive Kit Plus are not described on this App’s Website, nor anywhere else, including my Dealer that had no information or experience with this Kit and this App until it was just installed in my SLK. Mercedes-Benz has done an uncharacteristically poor job testing and designing how this App and Drive Kit Plus can and is really used by customers in their vehicles, unlike nearly everything else I’ve come to expect from this age-old company. Drive Kit Plus simply feels like more of a skunk-works early implementation — not something that is a premium $1200 parts & labor option available from a premium luxury brand.