In this proceeding we discuss as quantum correlations can enhance measurements capabilities [1,2,3,6], discussing few examples as target detection in a noisy environment and holometer. The first  is a quantum enhanced scheme preserving a strong advantage over classical counterparts even in presence of large amount of noise and losses. Our work, inspired by , has been performed exploiting only photon number correlations in twin beams. Thus, for its simplicity it can find widespread use. Even more important by challenging the common believe that real application of quantum technologies is limited by fragility to noise and losses, it paves the way to their real application. Then, we describe as the same kind of correlations can find application in a completely different area of physics, i.e. in testing quantum gravity. Indeed, recently, effects in interferometers connected to noncommutativity of position variables in different directions were considered in two coupled interferometers , the ``holometer'' . We show that the use of quantum correlated light beams could lead to significant improvements.