have noticed that there are no reviews for the Sierra OS on the App store and would like to know if the following options exist in Sierra? 1) Since Apple has a App store a user should be able to remove all pre-installed Apps from their operating system so that only the Apps that the user wants can be installed. 2) Can you view log in and log out of an account using the "console app" on a Sierra Mac? 3) The lock mechanism that prevents access to specific systems like Network settings "click the lock to make changes" does not have a automatic lock in a specific time period in previous versions. This would allow the lock to automatically lock after a period of say 5 minutes if you forget. Does Sierra have that option? It existed in Snow Leopard Anyone using Sierra can answer these questions?