The first is the AppRadio app itself, which powers the icon-based AppRadio interface. It's a free app that includes instructions for pairing your smartphone with the AppRadio hardware. For iOS users, this is the only app that you'll need to install, but Android users will need to install one more helper app.
That app is the CarKeyboard, which is a keyboard replacement that enables the AppRadio's touch screen to accept and pass on input to the apps running on your phone. This keyboard must be set as your input method when using AppRadio 3, so if you already have a favorite custom keyboard (such as Swype, SwiftKey, or the default Android keyboard) you'll have to switch back and forth when entering or exiting the vehicle. It's a little annoying, all of this keyboard switching, but I was able to use the third-party automation app Tasker (video) to automatically set my Input Method to CarKeyboard when connected to AppRadio and back to my preferred keyboard when I exited the vehicle. Pioneer should consider building a similar functionality into the next version of its app.
With the apps installed, the next step is to pair your handset with the AppRadio 3's Bluetooth system and then connect physically via one of the methods mentioned above. The AppRadio app should launch and, after a quick touch-screen calibration, you'll be ready to install and run your other apps.
From the icon-based AppRadio interface, you'll be able to see and launch any AppRadio-compatible apps that are installed on your handset. You'll also be able to see a list of compatible apps that are not installed and link to the Google Play Store or iTunes App Store to install them.
A full, constantly updating list of compatible apps for both platforms can be found on Pioneer's Web site. Cross-platform standouts include CNET favorite Waze for turn-by-turn navigation, Inrix Traffic, iHeartRadio for audio streaming, and the DashCommand driving-performance monitor. iOS users have a slightly larger number of compatible apps with exclusives like the Sygic, iGo, and MotionX navigation apps, Parkopedia parking assistant, and the Escort Live traffic and red-light camera alerts database.
On the Android side, Glympse is a simple app that sends live-updating location information to friends or family, allowing them to track your location online.
Apps that make use of GPS positioning benefit from being connected to the AppRadio 3's external GPS antenna, which should be more accurate than the A-GPS sensor in most handsets.
On either platform, in order to browse and play back media stored locally on the smartphone, you'll need to install a CarMediaPlayer app that scans your phone's storage and displays your songs on the touch-screen interface. Compatibility with the stock iPod app or Google Play Music apps would be preferable here. iOS users have the additional option of simply disconnecting from the HDMI port and connecting directly to USB to enable native browsing and playback from outside of the app-mirroring portion of the AppRadio 3's interface.
Of the apps compatible with the AppRadio 3, Pandora is the odd bird. Rather than mirroring the app over HDMI like the rest, Pandora uses either the USB port or the Bluetooth connection to connect to the app, directly displaying in its own interface outside of the AppRadio mirroring. It's a bit weird that Pandora is treated uniquely, but it also means that guests and passengers with handsets that aren't supported by the AppRadio 3's app mirroring can still connect to the head unit and enjoy their music. Likewise, the new Bluetooth audio-streaming capability allows a similar level of flexibility with a wider range of handsets.
The accidental second screen
All phones that I tested required that the handset's screen stay unlocked and lit when mirroring apps to the AppRadio's interface. This means that you or a passenger can continue to interact with the current app using the phone's touch screen. However, the receiver locks out onscreen display of unsupported apps while driving, so trying to fire up Netflix, Twitter, or YouTube will be met with a "not while driving" warning on the AppRadio's 7-inch screen.
This requirement that the phone screen be on means that you end up with a second tiny screen glowing at you from the cupholder when driving at night, and also it can be accidentally tapped by a passenger, which can be frustrating. Accidentally hitting the Home key, for example, would cause the AppRadio to lock its display because the launcher is not an AppRadio-compatible app. Locking the phone's screen caused the AppRadio to go totally blank, which doesn't solve the problem. This is admittedly a flaw in the way phones handle HDMI output.
When it comes to the sheer volume of compatible apps, the AppRadio 3 is only matched by the Parrot Asteroid Smart. However, the AppRadio makes use of the apps you already have installed and updated on your phone, whereas the Parrot requires its users to manage a separate Asteroid Market app store, which can be frustrating. I'm giving the edge to the AppRadio for ease of use.
However, the AppRadio's reliance on app mirroring and video adapters means that its initial setup is more involved and expensive. This SPH-DA210 version of the AppRadio 3, which includes the DVD player, retails for $500, but if you wanted to use it with an iPhone 5S you'd have to shell out an additional $120 in Apple and Pioneer adapters, bringing the total cost to about $620 plus installation. Android and iPhone 4 users don't have it much better; their totals with adapters sits at about $560. On one hand, that's a lot of money, but still significantly cheaper than the $1,000-plus GPS navigation receivers that were common and popular just a few short years ago. On the other hand, for less money a DIYer could conceivably mount a Wi-Fi-tethered iPad Mini or a Nexus 7 on the dashboard and achieve a similar result -- though the result may be less polished and in a dangerous legal gray area.
Pioneer offers a mech-free version of the AppRadio 3 SPH-DA110 that doesn't include the optical DVD drive or the motors to move the screen for it for $400. If you don't plan on watching movies while parked, I'd recommend you take the $100 savings and go with this model. Consider also the nearly identical AppRadio 2, which is still available at about $350, if you don't need the DVD player, can live without Bluetooth streaming, or don't own a MirrorLink phone.