When I was submitting my application on the common app, I forgot to do the checklist and signature. They just emailed me this morning notifying me that my application wasn’t submitted, and so I just submitted my signature. Should I send them an email letting them know about this? Thanks guys!
No, it won’t hurt your chances, and it’s not worth bothering Admissions about it with an email. See: http://talk.collegeconfidential.com/yale-university/1953106-deadline-extension.html#latest