FORTUNE — Good Technology, a Motorola spin-off that sells a secure app development platform to government agencies and 50 of the Fortune 100 companies, reported Thursday that activations of custom-made mobile apps are growing at a “staggering pace” among its 5,000 clients, and that Apple’s (AAPL) iOS is the clear favorite.
The attached chart shows the number of mobile devices activated among Good’s clients over the past two quarters. iOS accounted for 69% in Q2 and 72% in Q3. In the same periods, Google’s (GOOG) Android’s share declined from 27% to 23%.
Apple’s lead is even more dramatic in terms of the number of custom apps created on Good’s platform. Of the more than 1,000 apps developed internally by Good’s clients, 95% were iOS apps in Q3, down from 98% in Q2.
Secure document editing represented the single largest category of app (56%) and grew the fastest (up 45% from Q2 to Q3). Although most of those documents are in Microsoft (MSFT) Office formats (Powerpoint, Excel, Word, pdf), Microsoft’s mobile devices still haven’t caught on in the enterprise. Among Good’s customers, Windows Phone activations accounted for no more than 1% to total activations in each of the past two quarters.