Floer theory comes in various flavours and has developed into a primary tool in low-dimensional topology. In this talk, I will discuss the construction of an equivariant Seiberg–Witten–Floer homology associated to finite group actions on rational homology 3-spheres. This gives rise to a series of numerical invariants and I will survey some of their applications in knot theory, to equivariant embeddings and as obstructions to extending group actions to bounding 4-manifolds. This is joint work with David Baraglia.