Snapchat’s just-released IPO filing reveals that the app sees far more usage on Apple’s iOS mobile operating system than on Android. That trend has led the company to focus development resources on the iPhone experience, leaving Android lower down in the priority list. “We have prioritized development of our products to operate with iOS operating systems rather than smartphones with Android operating systems,” the company said in its S-1 filing.

Snapchat is very aware that consumers with an Android smartphone from Samsung, LG, Google, HTC, and other vendors aren’t getting an app that matches its iOS counterpart in quality. “If we are unable to improve operability of our products on smartphones with Android operating systems, and those smartphones become more popular and fewer people use smartphones with iOS operating systems, our business could be seriously harmed” the company says in the S-1’s business risks section.

Android has a large lead over iOS in terms of overall worldwide smartphone marketshare, but clearly there’s no correlation between those percentages and Snapchat’s adoption / daily usage among the app’s millions of users. Android users have in the past complained about video quality differences between the two mobile platforms, and Snapchat is often cited as one of those apps that just feels better and smoother on iPhones, even if the experience is meant to be similar. Now Android owners have direct confirmation that they’re second-class Snapchat users, and Snap recognizes there’s work to be done.