The market for indie apps is far better on Apple devices in general. More people are willing to pay for an ad free, nicely integrated app than on Android.
As for paid versions of Monument Valley, sales from the iTunes App Store far outpace sales on other marketplaces. Purchases on iOS account for 73 percent of Ustwo's $14.4 million of revenue, while only 17 percent of that total revenue came from Google Play.
Do you think it was a random factor that had it debut on iOS.
Despite far fewer devices, the Apple App Store has always made more revenue than Android. The most recent real numbers [0] I could find show this is a big difference.
I always assumed that’s why app devs roll out on iOS first.
I didn't contest the overall conclusion, but as engineers and entrepreneurs we normally have a propensity to disregard binary thinking. The numbers in your link are useful to predict expected revenue from an iOS vs an Android exclusive. The 73/17 ratio from the parent post is not, but could be misleading to someone who didn't know the app's release schedule.