Lisa stands for "LiPo-Saver". This small controller will protect your 2 or 3 cell Lithium Polymer battery from being discharged under the critical limit and thus to extend the life-time of the battery. The difference to other LiPo savers (which only give an optical or acoustical signal if the voltage falls under a limit) is the fact that LiSa will automatically disconnect the output load from the LiPo battery.
Another functionality is the built-in 5V voltage regulator which can deliver 1A in continuous operation.
See the manual here.