Though Apple's standard keyboard is quite good, there are several third-party keyboard apps like, Gboard which boasts of more features and is a delight to use. That's why iPhone and iPad owners enjoy typing on the custom keyboards with more flare.
Setting up a third-party keyboard as the default option on iOS devices is pretty simple. (Settings>General>Keyboard>Keyboard>Add New Keyboard). However, the custom keyboards will switch back to the default one every now and then especially in stock apps like Safari and Messages; making you puzzled why it happens. Nonetheless, there is a way to fix it.
(Remember, while entering passwords, the keyboard automatically switches back to the standard one in order to provide security to your information.)
Step #1. Launch Settings app on your iOS device.
What sort of changes would you like to see in the standard keyboard in the upcoming iOS 10? Fortunately, there are plenty of good-looking concept features which can immensely transform the user-experience of the next-gen iOS.