  Despite the impressive progress achieved both by X-ray and gamma-ray
observatories in the last few decades, the energy range between
$\sim200\;\mathrm{keV}$ and $\sim50\;\mathrm{MeV}$ remains poorly explored.
COMPTEL, on-board the Compton Gamma-Ray Observatory (CGRO, $1991$-$2000$),
opened the MeV gamma-ray band as a new window to astronomy, performing the
first all-sky survey in the energy range from $0.75$ to $30\;\mathrm{MeV}$.
More than $20$ years after the de-orbit of CGRO, no successor mission is yet
operating. Over the past years many concepts have been proposed, for new
observatories exploring different configurations and imaging techniques; a
selection of the most recent ones includes AMEGO, ETCC, GECCO and COSI. We
propose here a novel concept for a Compton telescope based on the CubeSat
standard, named MeVCube, with the advantages of small cost and relatively short
development time. The scientific payload is based on two layers of pixelated
Cadmium-Zinc-Telluride (CdZnTe) detectors, coupled with low-power read-out
electronics (ASIC, VATA450.3). The performance of the read-out electronics and
CdZnTe custom designed detectors have been measured extensively at DESY. The
performance of the telescope is accessed through simulations: despite a small
effective area limited to a few $\mathrm{cm}^{2}$, MeVCube can reach an angular
resolution of $1.5^{\circ}$ and a sensitivity comparable to the one achieved by
the last generation of large-scale satellites like COMPTEL and INTEGRAL.
Combined with a large field-of-view and a moderate cost, MeVCube can be a
powerful instrument for transient observations and searches of electromagnetic
counterparts of gravitational wave events.
