  We study light curves and spectra (equivalent widths of the iron line and
some other spectral characteristics) which arise by reflection on the surface
of an accretion disc, following its illumination by a primary off-axis source -
an X-ray 'flare', assumed to be a point-like source just above the accretion
disc resulting in a spot with radius dr/r<1. We consider General Relativity
effects (energy shifts, light bending, time delays) near a rotating black hole,
and we find them all important, including the light bending and delay
amplification due to the spot motion. For some sets of parameters the reflected
flux exceeds the flux from the primary component. We show that the
orbit-induced variations of the equivalent width with respect to its mean value
can be as high as 30% for the observer's inclination of 30 degrees, and much
more at higher inclinations. We calculate the ratio of the reflected flux to
the primary flux and the hardness ratio which we find to vary significantly
with the spot phase mainly for small orbital radii. This offers the chance to
estimate the lower limit of the black hole spin if the flare arises close to
the black hole.
