Produced with Petawatt (PW) class lasers, X-ray and Gamma-ray sources based on Laser-Plasma-Accelerators (LPA) will reach unprecedented brightness. They could become very useful tools for applications such as single shot pump-probe x-ray diffraction/absorption experiments, diagnostics for dense plasmas, but also to start exploring Strong Field Quantum Electro-Dynamic (SFQED) processes. In this experimental campaign, we propose produce Gamma-ray radiation using all-optical Compton scattering. In this mechanism, gamma-ray radiation is produced at the collision of relativistic electrons from a LPA with an intense counter-propagating laser pulse. In our scheme, the laser that drives the LPA is back-reflected by a plasma mirror and then collides with the electrons beam. In the first part of the experiment we will characterize the accelerated electrons and the Betatron radiation. In a second step, we will produce and characterize the Compton scattering radiation. Then, by means of plasma density tailoring, we will increase the intensity of the back reflected laser pulse and estimate its intensity through the measurement of the gamma-ray features. At the experiment, we anticipate that the GeV electron beams currently produced at LFA-Apollon will generate intense femtosecond radiation beams at energies from a few tens of keV (Betatron) to a few hundreds of MeV (Compton). Furthermore, this experiment is a first step toward the future SFQED experiments, such as pairs creation through the non-linear Brett-Wheeler process, that can be performed with the future 10 PW Apollon.