A wireframe is simply a diagram of your app. It doesn’t have to be beautiful. It does have to be comprehensive. It is the link between what’s in your head, and what will eventually appear in physical form on the App Store or Google Play. It needs to show everything that happens in the app,… 

NDA means non disclosure agreement. It is a contract which you and your developer both sign, attesting that your developer will respect the confidentiality of the information you provide. It frees you to talk about your ideas, so have one in place before you begin any kind of detailed discussion. For more information and sample:…