There is an Austrian company called AviBit. They developed electronic flight strips (amongst ASMGCS and so on) a decade ago for the new TWR in LOWW.
It is the first and only system that has been developed by ATCOs only and offers very good usability (because of the ATCO influence).
They sold it to England, Nepal, Saudi Arabia, Romania, Germany and so on for all TWR, APP and ACC. It is worth to have a look at!