Query about launching first Android vs. iOS

Hello. I'm doing some small research on the perceptual synergies between launching first on Android or iOS. If you could spend 3min doing this query, I'd be very thankful. And by the way, what do you think about this? The real question behind the query is: "do iOS users decrease their usage of an app after an Android launch?". I think they do but give me your answers please. :)