How do I know if my phone is being hacked?

I have the same question, however I'm sure they had access to my phone briefly and my password. I have already changed my account and password info from another computer and location. Before I make my update I need to try and verify if it is jail broken or some sort of spy app installed. I was caught off guard, but that wont happen again! Could you possibly tell me roughly what I should find? I'm 99.9 percent positive about this.