Mobile? Check. Desktop? Check. Tablet? Check.
Do you have the specific screen sizes for every kind specific device out there? Um… Well… what are the more popular ones? Should you build for those first?
That’s not a question that anyone can answer for you but there is a tool that can help you make that decision:
With Screen Sizes you can see the specific screen specs for the devices that are the most popular which is calculated from Google queries.
It’s worth a bookmark and at least a review as you work on your mobile implementations. Hope it helps!