Has he actually tried to talk to you about giving your relationship another chance, or are you just interpreting his behavior as a sign that he wants to? I would tread carefully on this one. I'm not saying you shouldn't get back together with him, if he's done some quality soul-searching during his time being single, and he is ready for a real relationship, then that's great. You can talk about pursuing that together. But keep in mind that old habits die hard (for lack of a better cliche) and you want to be sure that you won't run into the same problems if you get back together. Also, it's worth asking how you've been able to work through your trust issues... have you done that? Are you able to leave your SO's phone alone and not read through their private property? It's important to trust the person you're with until they give you a reason not to. I know that he did give you a reason not to trust him before, but if you are going to start over from scratch with him, you are going to have to give him the benefit of the doubt. Otherwise the same issues will come up again like they did before, and if you go snooping for things in someone's social media/phone messages, you will find them.
"Caring is not an advantage."