I am currently the main admin and I will be leaving the organization. Do I have the ability to make someone else the account administer and remove me or do we need to request that through you?
You are able to do this. When you are ready to make that switch, login and go to the Set Up tab, and then to Profile. Here, you can change the information over to the new person. You can also change the username here. To change the password, you will need to log out, and then click the "Reset Password" link. Enter the new username and that person will get an email to set up the password.
If the new admin is someone who already has a Visit Tracker account, they will need a different username than the one they are currently using. You can a number of something to the end.