Convenient and funny the sim-free application Flash SMS allows you (in most cases) to send full Screen real SMS without any sender.
Flash SMS “Class 0” SMS are handled differently regarding operator and smartphone.
For example in USA with “American Telephone & Telegraph” and a iPhone as recipient, the SMS will be
# Delivered directly on full screen
# Without any sender
# Not stored on SMS
# Only with a “Dismiss” Button
In the worst case, it will be handled as regular SMS with Flash SMS as sender (or even a short number if the recipient