RE: Time And Attendance for GP2013
Barry, in GP2013 there was a tool that provided external access to the end user to record their time and attendance and that tool was called Business Portal.
Business Portal is being phased out and by the time you move to GP2015 all the features that you might have used in GP2013 and Business Portal will have been replaced by 'internalized' applications that are accessed via the Web Client.
Business Portal allows (in GP2013 and before) end users without access to the direct GP client to enter time and attendance. This is now replaced with a Web Client (starting in GP2013) in GP2015 that replaces the need to implement an external tool on a SharePoint platform to complete the same task.
So, while there are tools out there, you might want to investigate GP2015 and all of the 'new features' that are included in the 'core' solution before you go hunting for an external 'add-on' solution.
Hope this helps.