Linear-Optical Feynman Paths (LOFP) is a C++ package for the strong simulation, that is, the exact calculation of probability amplitudes, of Fock-state boson sampling experiments on planar multimode interferometers. LOFP uses a Feynman path sum approach, together with tensor contraction. LOFP also includes routines with implementations of general-purpose permanent calculation algorithms for benchmarking purposes and examples. The code is advantageous with respect to general algorithms for permanent calculation for constant-depth circuits, and high density of photons per mode.