Check out this video of Mavis Co-Founder, Dr Phil, as he dives into the Monitor Tools (including Scopes) inside Mavis Camera:
Scopes can be overlaid to provide real time analysis on the exposure, hue and saturation of the image. For more information on what the scopes mean and how they can be understood, checkout the Waveform article and Vectorscope article.
Further settings can be found by tap holding down the Scopes icon, or accessed via the settings menus. You can select which scopes to display, along with the size and opacity of them.