In this paper we describe different applications we have ported to Intel Xeon Phi architectures, analyzing their performance. The applications cover a wide range. Alya, which is an HPC-based multi-physics code for parallel computers capable of solving coupled engineering problems in non-structured meshes. Waris, which is a simulation code for Cartesian meshes, that uses efficiently well-ordered data and well-balanced parallel threads. The last analysis is performed for a cornerstone of several simulation codes, a Cholesky decomposition method. The results are very promising, showing the great flexibility and power of Xeon Phi architectures.