Amazon Basics Bluetooth Keyboard
For users that want an affordable iPhone 6 Plus Bluetooth keyboard, the Amazon Basics is a good one to start with. This allows you to see how you would use a keyboard and how often you need one before spending more on a lighter model with more features.
The Amazon Basics Bluetooth keyboard is available in black and runs on two AAA batteries. This is close to a full size keyboard with a number row and function keys to control your iPhone 6 Plus.
$26 at Amazon