A very easy way to check for system updates
Now it's easy to know more information about system updates. Go to Settings > About phone > System updates & you can see when was the last time the system has checked for updates. There's also a Check now button that checks for updates instantly which is a very user-friendly alternative to dialing *#*#checkin#*#* or *#*#2432546#*#*
More information about unknown callers
Now it's easier to know more information about callers that are not in your contact list as the caller's country is displayed in the call log for these numbers.
Upload & download signals for WiFi
Upload & download signals are now shown on top of the WiFi signal indicator to let you know that transfer is in progress. Such signals were only previously available for mobile data connections like 3G.
Built-in owner info
Android 4 now offers a built-in feature to display owner information on the unlock screen which is useful in case the phone got lost. This feature can be found in Settings > Security > Owner info
Multiple account support for Google Talk
If you only have one Google account on your phone, you probably haven't noticed this, but Google Talk now supports multiple accounts.
Problems connecting Android 4 devices through USB on Mac & Linux
Since version 3, Android has switched from using Mass Storage Protocol to Media Transfer Protocol which is suppose to be better but it's not natively supported on Mac & Linux.
For Mac users, there's an easy solution which is downloading Google's Android File Transfer tool.
For Linux, you either need to figure your way around a good MTP client & configure things manually, or check if your device supports behaving as a camera when connected to a computer. You can check this by going to Settings > Storage & from the menu choose USB computer connection then switch from using Media Device (MTP) to Camera (PTP).
Phone settings location
I found it very hard at the beginning to find the Phone settings as it is no where in the settings menu. Finally I discovered that now it can only be accessed by going to the Phone app & selecting Settings from the menu.
|Phone settings on Nexus S|
Removing the search bar
The search bar in Android 4 is fixed on every screen of the desktop. Yet you can still remove it by going to Settings > Apps > ALL tab & press on the Google Search application. Then press Disable. I really do NOT encourage you to do that as the screen space recovered can not be used for anything else anyway & who knows what other functionality you might be disabling by doing this.
Gmail icons are confusing
The icons in the Gmail application can be very confusing. If you can't figure out what a certain icon represents, just long press on that icon & its description will appear.
The sync icon has been removed
There is no work around for this, but I thought that I need to let you know that there is no notification icon displayed for an account being synced anymore (sucks, I know).
There's still no native toggle widget for mobile data
I'm sad to say that there is still no native widget to toggle the state of the mobile data connection. I hoped that it would be included in the Power control widget. Until then, I recommend the Data Enabler app as a solution; it works great & it's very fast.
A very cool Easter egg!
If you go to Settings > About Phone & press Android version repeatedly, you'll be shown an image of an Ice-Cream Sandwich Android. As cool at it is, that's not all! If you press & hold on that image, it keeps getting bigger & bigger until a flood of Androids start flying on your screen!
That's all I have for now, enjoy using your Android 4 phone!