You can ask someone (and this is common), "How are you getting on?". Or, "I've got to get on with my life, even though we broke up", "They seem to get on really well, eve though they are vert different". As for flare up, you can also say "The fire flared up as the paper started to burn", "His temper really flared up at the meeting" etc. It can also be used as a term for medical condition, like something getting worse or suddenly returning. For example, "Students often find that their acne flares up before and during exams."