Too Long; Didn't Read
The USPTO (US Patent & Trademark Office) recommends performing a patent search before attempting to file a patent. Your app needs to qualify as “novel” This means that it needs to be different from all previous inventions in at least one constituent element. Your patent must spell out in explicit detail how the app will work. You can’t patent the code of your app, but the app as a whole falls under the category of “method” or “process” Methods and processes can be patented along with machines, articles of manufacture, and compositions of matter.