Unity does not have and traditional application menut which respects a xdg application menu spec, which TLDC relies upon. The new fancy way is having a "lens" to search for installed applications / documents at hand for open / start. However it seems like that applications are somehow categorized and could probably be customized of what is shown or not to be, we need to investigate how this is done to make TLDC work with unity.
See also bug #5210.
Seeing as Unity isn't shipped with Ubuntu anymore and the fact that we haven't seen any interest of this from any customers - we won't be looking into this.