Are there any chat apps that have been optimized for iPhone 6/6+?
iMessage My favourite chat app on iOS. And almost the most important feature of the iPhone to me
Integrates with the OS of the phone superbly
Delivery and Read Reports. Notice of the other person typing
Send pics, videos, voice notes
No compressing of images and stripping out EXIF data (So important to me, a quick way to send your photos in their native res)
Minimal compressing of videos. Compresses higher rate videos down to 720p/30fps
Group functionality
Location functionality
Desktop version on OS X
Integrates with all of your iOS/OSX devices, send/reply to conversations from either
But yes - iOS/OSX to iOS/OSX only.
Other than that...no other chat apps are updated. I also have WhatsApp, Tango, Skype, Viber and Blackberry Messenger and none of them are updated.