We use a Frequentis software on Waco tablets for electronic flight strips, at the three main trunk airport towers in NZ.
I wouldn't recommend the system to anyone. That said, there are some elements of functionality that are rather useful. I just wish that it was a more user-friendly and reliable platform.
When we recently had to move to the contingency tower for a weekend, it wasn't too much trouble re-adapting to paper strips. The failure rate was rather low.