Have the latest releases to Windows IoT included an On Screen Keyboard? I am aware of other suggestions that use the webview to provide a keyboard, but I would prefer an OSK
It is available in the latest preview release (14986). See de image bellow. On the left the device portal, on the right a screenshot of the device.
Edit
About the internationalization, the only thing I've found until now is the keyboard layout option, on the device settings, but it seems to not be working yet, cause I don't see the "Ç" character that should be present in a pt-br keyboard.