In this talk we will discuss impurity-induced bound states in topological and trivial superconductors, the so-called Shiba states. We have found that the spin-polarised (SP) spectral properties of these states give access to various properties of the host superconductor. As an illustration, we will show that the SP local density of states (a quantity measurable with SP STM) allows to extract the spin-orbit momentum vector in s-wave superconductors with Rashba spin-orbit interaction. In p-wave superconductors the same quantity gives access to the spin-triplet pairing vector of the host material and thus helps to distinguish between different types of unconventional pairing. Moreover, in a superconductor with a mixed singlet-triplet pairing, our analysis allows to unambiguously discriminate a non-topological superconducting phase from a topological one, in other words to determine whether it is in an s-wave or p-wave dominating phase. And finally, we show promising setups for engineering topological phases from Shiba states where a controllable topological phase transition emerges.