Going Crazy Looking For Clues

Sometimes I feel like a crazy person the way I have to go thru things. My husband often lies to me about everything and anything. Seemingly for no reason?
He has come home extremely late. He has made plans with friends but not told me about them. Said he is stuck in traffic when he is really at the bar. It makes me constantly question why he is lying and wonder if there are other things that I am missing. Big things like affairs, girlfriends. Who knows!!! In general I don't think he seems the type but really if you think about it..... No one ever gets married with the expectation of their husband having an affair. I think that one usually takes you by surprise. So now I have been going crazy looking they the computer history, his email, his phone an admittedly using a tracking app. He installed the app incase his phone is ever stolen. But I have been using it to figure out where he really is. I do not like going thru all his stuff. In general I would feel a lot better if I didn't feel like I had to. I just can't trust what he is saying. I've tried telling him this but I don't think he really takes it seriously. He hasn't really done anything to make me trust him. I wouldn't care where he was ( to an extent) if he was just honest about it.