Enterprise E4 or E3 plan users can download the entire Office 2013 suite (Office 365 ProPlus) and the Lync 2013 and OneDrive for Business 2013 and install them in their Desktops and Laptops (maximum 5 active devices) by going to the Outlook Web Apps ->Setting -> Office 365settings -> Software. The Office suite is available for Offline access for this subscribers.
Enterprise E1 Plan users can download and install only Lync 2013 and OneDrive for Business 2013 in their systems. This will of course get installed alongside the existing licensed MS Office 2007/2010/2013 if at all installed already in the respective systems.
The Lync 2013 app and the OneDrive for Business app are available for free downloads from the respective mobile phone stores that one is using - Google store for Android phones, iStore for iPhones and Windows store for Windows phones. These apps give the user a better experience than just accessing the features using just the browser.
Yammer also has an app for download from the respective stores. This is applicable for both E1 as well as E3/E4 users.
Lync software / app brings to the users the presence, IM, audio meeting and conferencing and video meeting and conferencing and live meeting capabilities.
OneDrive for Business software installs as a folder in the user's local hard-drive that syncs with the cloud automatically. It also becomes a favourites folder in the Windows explorer (File explorer). Just a drag and drop of the files or folders from the local drive to the OneDrive for Business folder under Favourites creates a synced copy in the cloud. The app instals as Office mobile in the smartphones and enables access to the files here from anywhere you are.