Admin access allows the person full control over the location, such as the ability to change the Access permission level to other contacts - there can only be 1 such user and this user cannot be changed at this time. The Admin role is automatically assigned to the account holder who setup the Location.
If you must change the Admin owner of a location, the only way to do so currently is to delete the Company or Location and re-create it using the app when signed in under the desired account. In the future, we hope to offer the ability change the Admin more easily.
Admin vs Primary Contact
Note: The Admin owner for a location refers to the owner of the location - this is the person who setup the Location under their own account. This is not to be confused with a Primary Contact for a Location, which is simply a contact who gets automatically added onto notifications & reports for locations.