In your app, every Textbox has the ability to have an InputScope assigned to it.
<TextBox InputScope="Text" />
InputScope help the developer to assign also the good keyboard for the context:
- URL: this keyboard gives you a ".com" button to finish typing your URLs, but that button, with a long-tap, will also expand to show you .net, .org, .edu, and .co.uk.
- TelephoneNumber: it gives the user a numeric dial pad instead of an alphabetic keyboard.
- EmailNameOrAddress: it gives a period, an @ symbol and ".com" button.
You can find more InputScopeNameValue enumerator on MSDN.