The home page has a banner at the top, a series of columns below where you can add apps, and a footer at the bottom.
Click on the "+ Add App" button at the bottom to select the app you want to use, and then click on the app icon that appears to drag it over one of the areas labeled "AVAILABLE". Click here to see a list of all of the apps available to use. Each app can be rearranged on the page by clicking on the icon with the vertical arrows 
in the upper left corner and dragging it into another location on the page.
You can also change the layout of the columns on the home page by clicking on the "Settings" button at the bottom and then selecting a new layout from the list of thumbnail images. The apps you've added to the home page will automatically move when you change the layout, but not all layouts have the same number of columns so some apps may be hidden.