As people have mentioned - who cares if it exists, everything exists in some shape and if it didn't exist, it probably doesn't have a market anyway! If you can

As people have mentioned - who cares if it exists, everything exists in some shape and if it didn't exist, it probably doesn't have a market anyway! If you can do it better, you can succeed. (though don't try, for example, to create a mail app like Gmail, you will probably never keep up with them!)