Assuming you mean Customer Relations Management and not Crew Resource Management, because CRM in aviation is the later, as alluded to above. Using the former as the basis for your acronym, there are a few CRMs out there used by flight schools, of which Times2Fly, Flight Schedule Pro, and Flight Circle are the two brought up often on other forums. There's also the likes of Private Radar, Hold Short, Schedule Master, MyFBO, Needlenine, and a whole host of others. You could look at those to get an idea of what each application does and what it does not do, and find a niche for you to exploit.