  We examine some inflationary models based on modifications of gravity in the
light of Planck 2015 data, such as the generalised Chaplygin inspired
inflation, models based in $N=1$ supergravity and braneworld scenarios. We also
show that, conversely, potentials with a very flat plateau yield a primordial
spectrum similar to that of the Starobinsky model with no need to modify
general relativity.
