Android 4.4 KitKat added several new features such as immersive mode and Ok Google for various Android devices. However, there are important things lacking on Android KitKat and may be a good start for Android 4.5 to feature for 2014.
Due to fragmentation, Android devices look different from each other and it affects customisation options. Multiple themes and colour schemes are not very common on vanilla stock ROMs but available on certain brands such as Sony Xperia via Xperia Themes.
Additionally, widgets are very limited on the lock screen such as the lacking of Messaging lock screen widget on some Android models like Xperia SP running Android 4.3 Jelly Bean.
Default PC Manager
Google has not released a unified PC manager for Android devices even for Nexus. Users are obliged to download and install Samsung Kies or Sony PC Companion to manage multimedia files or firmware updates.
AirDroid is the common ground on all PC suites for Android devices and it allow users to manage calls and messages in addition to data files.
Smarter Camera App
Unfortunately, Google Now is not focused on camera functionality yet and it is more into queries and suggestions. Samsung and Sony managed to make the camera app on their devices smarter than Nexuses.
For example, you can use the camera app to grab online details about the image such as information about a landmark, a restaurant or an object using Info-Eye camera mode on selected Sony Xperia devices.
Unified Communication Centre
Google Hangouts is the equivalent app to the centralised communication featured on Skype on Windows Phone and iMessage on iOS 8. But Android devices are still far from each other as some brands monopolised the area.
ChatOn from Samsung allows Galaxy device users to perform live chats while Nexus users will need to stick with Hangouts or download neutral apps such as WeChat. BlackBerry Messenger may be a very old trick; however, it managed to unify every BlackBerry user.
More Intuitive Gestures
HTC Sense 6.0 features several gesture controls across the device it runs. Android notifications shade may have changed but still lacks the general idea of swiping from left to right and vice versa. Users are forced to use custom ROMs in order to get amazing intuitive actions for the home screen, lock screen and notifications tray.
Modify 'Ok Google'
You cannot modify the Ok Google phrase to activate its action unlike with other voice apps. A new syntax command should be allowed to open the service since Android OS is highly customisable. If not, why not offer other custom voice commands instead of just using the same old boring passphrase.
Android OS does not feature multi-window mode and users must turn their attention to Galaxy devices. Multi-window mode allows Android devices with larger screen display to use multiple apps at once which improves multitasking between video playback and email.
Android Jelly Bean featured personal accounts to secure private data files from other users. However, it is not as specific compared with Samsung's Kids Mode. Moreover, profiles are not available on default Android OS which some users are asking to set the device's mode at home or at work.
Sony Mobile installed Smart Connect that automatically recognises a mode whenever an accessory is attached such as WALKMAN being launched after connecting the headphones.
New Power Manager
Google improved the battery life on Android 4.4.3 KitKat but still lacks an independent power manager. Galaxy S5 has Ultra Power Saving Mode while Xperia Z2 features STAMINA mode like other Xperia devices.
Android devices running vanilla stock ROM must use third-party apps such as Juice Defender or Easy Battery Saver just to manage battery life and restrict background apps. It is already known that some apps are written poorly so why not create a default power manager that stop apps from draining power during idle mode or set the entire function to basic phone during low battery level.
Easier Backup and Restore
Backup of apps is a managed by your Google account and relayed through Google Play. However, there is no way to create backup copies of apps to the internal storage or microSD card without rooting the device and losing its warranty.
Sony features Backup and Restore as a native app that can create backup of every application on the device to the microSD card. This is considered important during reinstallation of apps after a reset without requiring downloading the files again from Google Play Store.