The short answer is yes, but the long answer is more complicated depending on your audience and where/how you need to be discovered…
iOS Devices Have Been Dominating Mobile Web Traffic For The Past 6 Months [Report] | Cult of Mac: “Android technically sells more smartphones than Apple, but iOS devices continue to dominate mobile web traffic. Chitika Insights has been tracking web traffic on the top mobile platforms, and iOS commands 67% of usage and Android only 33%.”
We generally start clients with iOS and web apps but don’t shy away from Android if the market is there.