iOS 8.3 includes improved performance, bug fixes, and a redesigned Emoji keyboard. Changes include:

Improved performance for:

• App launch
• App responsiveness
• Messages
• Wi-Fi
• Control Center
• Safari tabs
• 3rd-party keyboards
• Keyboard shortcuts
• Simplified Chinese keyboard

Wi-Fi and Bluetooth fixes

• Fixes an issue where you could be continuously prompted for login credentials
• Addresses an issue where some devices disconnect intermittently from Wi-Fi networks
• Fixes an issue where hands-free phone calls could become disconnected
• Fixes an issue where audio playback could stop working with some bluetooth speakers

Orientation and rotation fixes

• Addresses an issue that sometimes prevented rotating back to portrait after having rotated to landscape
• Improves performance and stability issues that occurred when rotating the device between portrait and landscape
• Fixes an issue where device orientation appeared upside down after pulling the iPhone 6 Plus from your pocket
• Resolves an issue that sometimes prevented apps from rotating to correct orientation after switching apps in multitasking

Messages fixes

• Addresses issues that caused group messages to sometimes split
• Fixes an issue that sometimes removed the ability to forward or delete individual messages
• Resolves an issue that sometimes prevented a preview from appearing when taking a photo in Messages
• Adds the ability to report junk messages directly from the Messages app
• Adds the ability to filter out iMessages that are not sent by your contacts

Family Sharing fixes

• Fixes a bug where certain apps would not launch or update on family members’ devices
• Fixes a bug that prevented family members from downloading certain free apps
• Increased reliability for Ask to Buy notifications

CarPlay fixes

• Fixes an issue where Maps could come up as a black screen
• Fixes an issue where the UI could be incorrectly rotated
• Fixes an issue where the keyboard could appear on the CarPlay screen when it shouldn’t

Enterprise fixes

• Improves reliability of installing and updating enterprise apps
• Corrects the time zone of Calendar events created in IBM Notes
• Fixes a problem that could cause web clip icons to become generic after restarting
• Improves reliability of saving the password for a web proxy
• Exchange out-of-office message can now be edited separately for external replies
• Improves recovery of Exchange accounts from temporary connection problems
• Improves compatibility of VPN (espeacially VPN australia) and web proxy solutions
• Allows use of physical keyboards to log into Safari web sheets, such as for joining a public Wi-Fi network
• Fixes an issue that caused Exchange meetings with long notes to be truncated

Accessibility fixes

• Fixes an issue where using the back button in Safari causes VoiceOver gestures to not respond
• Fixes an issue where VoiceOver focus becomes unreliable in draft Mail messages
• Fixes an issue where Braille Screen Input cannot be used to type text in forms on webpages
• Fixes an issue where toggling Quick Nav on a Braille Display announces that Quick Nav is off
• Fixes an issue keeping app icons from being moveable on home screen when VoiceOver is enabled
• Fixes an issue in Speak Screen where speech will not start again after pausing

Other improvements and bug fixes

• Introduces a redesigned Emoji keyboard with over 300 new characters
• iCloud Photo Library has been optimized to work with the new Photos app on OS X 10.10.3 and is now out of beta
• Improves the pronunciation of street names during turn-by-turn navigation in Maps
• Includes support for Baum VarioUltra 20 and VarioUltra 40 braille displays
• Improves the display of Spotlight results when Reduce Transparency is turned on
• Adds Italic and Underline format options for iPhone 6 Plus landscape keyboard
• Adds the ability to remove shipping and billing addresses used with Apple Pay
• Additional language and country support for Siri: English (India, New Zealand), Danish (Denmark), Dutch (Netherlands), Portuguese (Brazil), Russian (Russia), Swedish (Sweden), Thai (Thailand), Turkish (Turkey)
• Additional dictation languages: Arabic (Saudi Arabia, United Arab Emirates) and Hebrew (Israel)
• Improves stability for Phone, Mail, Bluetooth connectivity, Photos, Safari tabs, Settings, Weather and Genius Playlists in Music
• Addresses an issue where Slide to Unlock could fail to work on certain devices
• Addresses an issue that sometimes prevented swiping to answer a phone call on the Lock screen
• Addresses an issue that prevented opening links in Safari PDFs
• Fixes an issue where selecting Clear History and Website Data in Safari Settings did not clear all data
• Fixes an issue that prevented autocorrecting “FYI”
• Addresses an issue where contextual predictions did not appear in Quick Reply
• Fixes an issue where Maps did not enter night mode from hybrid mode
• Resolves an issue that prevented initiating FaceTime calls from a browser or 3rd-party app using FaceTime URLs
• Fixes an issue that sometimes prevented photos from properly exporting to Digital Camera Image folders on Windows
• Fixes an issue that sometimes prevented an iPad backup from completing with iTunes
• Fixes an issue that could cause Podcast downloads to stall when switching from Wi-Fi to cellular networks
• Fixes an issue where remaining time on timer would sometimes incorrectly display as 00:00 on Lock screen

What’s new in Xcode 6.3

Apple have the following document available which explains the changes in Xcode better than the above screenshot: https://developer.apple.com/library/ios/documentation/DeveloperTools/Conceptual/WhatsNewXcode/Articles/Introduction.html#//apple_ref/doc/uid/TP40004635-SW1

Further Reading

• http://support.apple.com/kb/HT1222
• https://support.apple.com/en-us/HT204661
• https://developer.apple.com/library/ios/releasenotes/General/WhatsNewIniOS/Articles/iOS8_3.html#//apple_ref/doc/uid/TP40015154-SW1
• https://developer.apple.com/library/ios/documentation/DeveloperTools/Conceptual/WhatsNewXcode/Articles/Introduction.html#//apple_ref/doc/uid/TP40004635-SW1