Yes I have and yes you are correct. There are two, a red and a green, and can be mild or spicy hot. The red is based on dried chiles, the green on cilantro. Neither are cooked though sometimes food (often fish) will be cooked in the sauce. The are generally served as accompaniments to, well, everything practically. They are ubiquitous on the Canary Islands and will nearly always be served, on the side, with fish, meat or poultry.
Olive oil, vinegar (usually sherry vin), garlic, paprika (or hotter red chiles) for the red mojo, cilantro in place of chilies for the green, are the standard ingredients. From there, spicing usually includes cumin, occasionally oregano, pepper and, of course, salt.