Hi Civuck, thanks for the response.
If I find a definitive answer I'll leave it here too. But my suspicion is that the aptX transfer is automatic and must be built into the firmware of the device that uses it whenever it streams Bluetooth.
Since aptX operates over the A2DP protocol Those devices that can see "see" aptX uses it and those that can't just see it as "normal" (I don't know what the standard compression algo would be called) over the A2DP profile for Bluetooth stereo.
I am working on a review of a Bluetooth "hi-fi" device that promises CD-like audio quality from your aptX device to any AV receiver with a digital optical input.
I tested it head-to-head with what has been the gold standard for Bluetooth-stereo receivers by Logitech, this one uses the analog stereo outs and is not aptX compliant.
The difference was amazing. Although the Logitech sounds okay, it still sounds like overly-compressed Bluetooth stereo, a real compromise in sound quality.
Using the device I'm reviewing using aptX the difference was significant. I am reasonably certain I was using the aptX codec judging by the differences in the transfer of the exact same music file head-to-head between the aptX and the non-aptX device where everything else in the audio chain was identical.
So, it's my conclusion that you don't have to screw around with installing software on your device to use aptX. I believe it's like cigarettes when you take-10 in the Army... you can smoke 'em if you got 'em.