How do you manage your contacts?

Hey guys, I am a freshman at a second-tier school on the west coast. I have been networking a lot with many people. Recently I have around 200+ contacts and emails. I have been using excel to check, but it is such a pain that you have to go through every single contacts on the list. Sometimes, I even forgot to follow up some contacts. What other apps are you guys using for managing your contacts and networking? Any Recommedations? Thanks a lot!