CarPlay isn't an app, so to speak.
You plug in/connect your iPhone via USB, and a few of the apps/functions will appear on the touchscreen in your Ford (and there will be some voice integration as well).
Late answer but you need two things for CarPlay on your 2016 F-150. First you need to have Ford's Sync 3 software upgraded to version 2.2. Ford pushed out this update in May in its first ever OTA update or you can download and install it with a USB stick. Second, and this a BIGGIE, the USB hub module on your 2016 F-150 needs to be replaced with Ford's CarPlay compatible hub. The part is about $70 and there are YouTube videos on how to install it yourself if you are so inclined. I had my 2016 F-150 XLT upgraded by my dealer and it cost me $275.00 part and labor. Ouch. But CarPlay now works just fine.
Not sure what you mean.
Does the truck say that it has CarPlay?
If so, then look at the manual or online to find out how to use it.
where to get Apple CarPlay
