  In a typical experiment in magnonics, thin films are magnetized in-plane and
spin waves only carry angular momentum along their spatial propagation
direction. Motivated by the experiments of Bozhko et al. [Phys. Rev. Research
2, 023324 (2020)], we show theoretically that for obliquely magnetized thin
films, exchange-dipolar spin waves are accompanied by a transverse
spin-current. We propose an experiment to electrically detect this transverse
spin-current with Pt strips on top of a YIG film, by comparing the induced
spin-current for spin waves with opposite momenta. We predict the relative
difference to be of the order $10^{-4}$, for magnetic fields tilted at least
$30^{\circ}$ out of plane. This transverse spin-current is the result of the
long range dipole-dipole interaction and the inversion symmetry breaking of the
interface.
