iOS 8.1 is now released today by Apple and very excited that is features like Apple Pay, Message from your iphone using your mac are now live.
iCloud Drive, for example, will allow iCloud users to store numerous files as they would on , Dropbox, Google Drive or Microsoft’s OneDrive. The iCloud we know is more of a back-up infrastructure that permits users to retain settings, photos, messages and the like on OS X and iOS, but with iCloud Drive, users will finally be able to store, manage and browse their files as they would in Finder.
Your phone will need at least 2.2 GB of free storage to process this update. You will also need to be on a WIFI network and battery at at over 50%.
Simply go to your phone's setting-Software Update .