StreetSign is a digital signage system, originally written for the TeenStreet 2013 (Germany) youth congress. It works with a single server, and multiple client computers connect over the network. It is lightweight enough that a Raspberry PI can run as the server for smaller installations.
Mathpump is a simplistic remote collaboration tool. It could be useful for those researchers who tend to think by drawing pictures (e.g. theoretical physics). Bob uses Inkscape to draw a picture, which is incrementally transmitted to the Alice's computer so she can look at it. She answers by drawing her own picture, which is transmitted to Bob. Transmission happens every time the SVG file is saved. The transmission is incremental; what is actually transmitted is the difference between the old version of the SVG file and the new one.
SIMtrace sniffs communication between a mobile phone and a SIM/USIM card. This can be useful for research and analysis, and for developing mobile phone and SIM toolkit (STK) software. The SIMtrace hardware is also capable of MITM (man in the middle) attacks on the SIM-MS communication.