GammaRay is a good tool ,but I ended up using valgrind and the problem with our app was in the desing ,having tons of (some times useless) widgets in memory at the same time.We are redesigning our user interface now instead of trying to fix a bad design.The design was done using only Qt Widgets mostly because of a lack of expertise in mobile development and QML in particular.We hope QML will ease some of the troubles we came across :-)