The smartphone platform wars are pretty much over, and Apple and Google won. But it's interesting, in passing, to note the final score, and think about what it means.

Globally, something around 5bn people (give or take perhaps 250m each way) have a mobile phone, out of around 5.5bn people over the age of 16. (This number is fuzzy because many people have more than one SIM card). This will rise to closer to 6bn over the next few years as the population and the penetration grow.

Apple said in January 2016 that it has "1 billion" active devices (a nicely rounded number), across the Mac, iPhone, iPad, iPod, Apple TV and watch. Of these there are around 90m Macs (Tim Cook said 80m in early 2014), something over 10m watches, closer to 20m Apple TVs and perhaps as many iPods still in use. That leaves something close to 900m iPhones and iPads. Apple has sold 318m iPads - if we assume a 3 year lifespan for iPhones and 4 years for iPads that gets an install base in December 2015 of 630m iPhones and 250m iPads, or 880m in total - close enough. Given both iPad and iPhone sales have been flat since then, this number probably hasn't changed much.

China Mobile said that in Q1 2016 15% of its 830m active base were using iPhones - so 125m of those 630m iPhones. China Mobile has 60% of Chinese mobile subscriptions (note as above, this is not the same as users per se), but as the premium operator it has 73% of 4G, which is probably more relevant. This implies something around 175m iPhones in China across all three operators. This is more iPhones than there are in the USA. (Note that not all of these were sold in China - this includes imported second-hand devices as well.)

Overall, the Chinese mobile operators reported 591m 4G subscribers in Q2 2016, and 808m combined 3G & 4G users at the end of 2015, when the Chinese government reported 620m mobile internet users (rising at a bit over 2% a quarter). One should be very cautious combining numbers from different sources with different methodology, but this implies that if there were 175m iPhones in Q1, that leaves perhaps 450m or so to be Android (or at least Android that go online). Of course, this is Chinese Android - not a fork, but lacking any Google services and excluded from Google's statistics. Meanwhile, the government also reports 220m people using tablets to go online (see footnote). It's not clear how many of these are shared, so one should round this down a bit.

Then we have Google Android (as opposed to Chinese Android). Google has always been constructively opaque about Android statistics, using shifting metrics that never quite reconciled with each other. The last time it gave a solid number for the active base was September 2015, when it said there were 1.4bn active Google Android users. According to the Android developer dashboard at that time, about 10% of the active base had a large or extra-large screen, implying a tablet - so, 1.25bn phones and 150m tablets, rounded. How much has this risen since? Well, on most estimates smartphone sales overall have been pretty flat for the last few quarters, with any marginal sales coming at the very low end (the entry price for Android is now well under $50). So this base might have risen by (say?) 100m, but probably no more. Plotting this as a chart (showing only Google's rounded numbers at scheduled events), a March 2016 number of 1.5bn total Google Android and hence 1.35bn phones looks plausible, and might be high.