Using MUSE observations from the GASP survey , we study 54 galaxies undergoing ram-pressure stripping ( RPS ) spanning a wide range in galaxy mass and host cluster mass . We use this rich sample to study how the star formation rate ( SFR ) in the tails of stripped gas depends on the properties of the galaxy and its host cluster . We show that the interplay between all the parameters involved is complex and that there is not a single , dominant one in shaping the observed amount of SFR . Hence , we develop a simple analytical approach to describe the mass fraction of stripped gas and the SFR in the tail , as a function of the cluster velocity dispersion , galaxy stellar mass , clustercentric distance and speed in the intracluster medium . Our model provides a good description of the observed gas truncation radius and of the fraction of star-formation rate ( SFR ) observed in the stripped tails , once we take into account the fact that the star formation efficiency in the tails is a factor \sim 5 lower than in the galaxy disc , in agreement with GASP ongoing \ion H1 and CO observations . We finally estimate the contribution of RPS to the intracluster light ( ICL ) and find that the average SFR in the tails of ram-pressure stripped gas is \sim 0.22 M _ { \sun } \mathrm { yr } ^ { -1 } per cluster . By extrapolating this result to evaluate the contribution to the ICL at different epochs , we compute an integrated average value per cluster of \sim 4 \times 10 ^ { 9 } M _ { \sun } of stars formed in the tails of RPS galaxies since z \sim 1 .