  In this paper we introduce a new fractional derivative with respect to
another function the so-called $\psi$-Hilfer fractional derivative. We discuss
some properties and important results of the fractional calculus. In this
sense, we present some uniformly convergent sequence of function results and
examples involving the Mittag-Leffler function with one parameter. Finally, we
present a wide class of integrals and fractional derivatives, by means of the
fractional integral with respect to another function and the $\psi$-Hilfer
fractional derivative.
