Timeline updates: The new Quick View feature allows users to see what's coming up next in the day right from their watchface. Pressing down on the watchface gives users access to current events.
App Glances: View information from your apps without having to open them.
4-Button Quick Launch: Customize your Pebble even further by assigning your favorite apps to each button for quicker access.
A Redesigned Health App: The new app focuses on simplicity and glanceability and reintroduces weekly charts to summarize your health activity. Pebblers can now access the health app by pressing the up button on their watchface, enabling quicker access to step and sleep activity.
Email Actions: iOS users can Reply, Delete, and Archive Gmail emails directly from the notifications on their watch through the Inbox, Gmail and Mail apps.
The evolution of Pebble Health has been fantastic and the usability improvements in 4.0 look great.
The smartphone updates are particularly welcome for iOS users who will see improved support for email actions that Android users have enjoyed for some time now. iOS users can now delete, archive, mark as read, reply all, and star emails received from Gmail accounts. Pebble users can reply to iOS Messages too.
Pebble Firmware 4.0 works with Pebble Time, Pebble Time Steel, Pebble Time Round, and the upcoming 2016 Pebble lineup (Pebble 2 and Time 2). Version 3.12.2 remains the most current firmware for Pebble Classic and Pebble Steel at this time. The Pebble apps for iPhone and Android work with all Pebble watches running Firmware 3.12 or higher.