  We construct a consistent model of gravity where the tensor graviton mode is
massive, while linearized equations for scalar and vector metric perturbations
are not modified. The Friedmann equation acquires an extra dark-energy
component leading to accelerated expansion. The mass of the graviton can be as
large as $\sim (10^{15}{cm})^{-1}$, being constrained by the pulsar timing
measurements. We argue that non-relativistic gravitational waves can comprise
the cold dark matter and may be detected by the future gravitational wave
searches.
