With so many new apps springing up constantly, some very useful apps tend not to get the attention they deserve and become undercover apps that are used by a very few who happen to discover them and their usefulness. Here are some undercover apps you’ve probably never heard of until now, but may be worth learning a little more about. 4 Weirdly Helpful Undercover Apps Vayable Vayable is an app that allows you to enhance your travel or vacation experiences.…