Monitoring user activity

How can I tell what a user is doing when logged onto the network? Is there a set of logs I can view, by user, that would show when they log onto the network and what apps they are in and how long they are in the apps?  The main thing I want to see is what they are doing. We have "work from home" employees and I think one of them is working a lot less than they say.  The main applications they use are Outlook and Internet Explorer where IE11 is being used to access our business application. I can have our programmer write an app that logs their activity in our business app, but before I have him do that I thought I would ask you guys if SBS 2008 has a set of logs that would tell me what I want to know.