Unless you want an app written in Arabic, it doesn't matter where the developer is located. The internet is just about as fast from you to the next house as it is from you to halfway around the world. And, since any experienced developer will insist on everything being in writing, you're going to be using email at first, a paper contract once you've agreed on the features and the price (and some developers even use electronic signature these days, so it's as fast as any other email), and email after the contract is signed. (You don't sit with the developer to explain things, you put them in writing. No one is going to invest time in developing something you talked about, only to have you change what you say when it's done - experienced developers have been there already.)