The Resistive Plate Chambers (RPCs) can be extensively used in Cosmic Ray Physics and Gamma-Ray Astronomy. Indeed, the ARGO-YBJ detector, a 7000 m$^2$ full coverage RPC carpet, was operated at YangBaJing (Tibet, 4300 m asl) with very low maintenance and excellent performance for more than a decade. It provided: high efficiency detection of low energy showers, down to 100 GeV, by means of the dense read-out sampling; wide energy range investigated, 100 GeV -- 10 PeV, by means of the combined digital/charge read-outs; good energy and angular resolutions with unprecedented details in the shower core region.

The RPC-based flare hunter we propose is therefore based on the experience of the ARGO-YBJ experiment.
A new RPC generation dedicated to cosmic ray experiments is in preparation, the main differences from ARGO-YBJ being the avalanche mode operation instead of streamer and the gas closed loop that strongly reduces the fresh gas consumption.

This contribution shows experimental results on several new generation prototypes that were built in view of a test experiment to be performed in the South hemisphere. The experiment can be carried out either as standalone or by installing the RPC layer on top of a water Cherenkov detector. The purpose of this hybrid detector would be to combine the RPC capability of imaging the shower front, down to few keV/hit, with the Cherenkov capability of integrating all signals produced by the shower in several radiation lengths of water. In both cases the RPCs would strongly increase the sensitivity to the observation of flaring phenomena like GRBs or AGNs below the TeV.