We know that TSMC and Samsung each manufacture versions of Apple's A9 SoC for the iPhone 6S and 6S Plus, and thanks to an enterprising developer, we might be learning more about how the sourcing of those chips is divided. According to data released by developer Hikaru Wang, it seems TSMC has made the majority of A9 chips in iPhones sold so far.
Some caveats: only users who have installed the developer's app are being counted, so there's no way this is a complete tally of iPhones. The developer hasn't said how many phones have participated in these shenanigans. Furthermore, the app isn't on the iOS App Store. Interested users have to install Wang's mobile device management profile, which gives an unvetted app free reign over the device.
Even so, Wang has posted the results he's collected with the app so far, showing which chips are in participating iPhones. Out of the devices that have installed and run the app, nearly six in ten—a hair over 57%—reportedly have chips made by TSMC.
Even though Chipworks found TSMC's chip to be the larger of the two, it seems Samsung's version has made its way into more iPhone 6S Plus samples. Over 55% of participating phones have a Samsung-made chip. The majority isn't overwhelming, though, and the margin of error is unknown. By contrast, TSMC's chip does seem to have a large majority of the smaller iPhone 6S. Just over 77% of sampled phones are apparently using the TSMC silicon.