The first new feature that this new update brings is Dynamic GPS, a feature that allows the Fitbit Charge 4 fitness bracelet to use the smartphone’s GPS sensor attached to the bracelet if it is close to capturing track and speed as well as other statistics. This should help save battery on Fitbit Charge 4 since it will not use the built-in GPS while carrying your phone with you.
The second feature that this update brings is Smart Wake in the alarm app, and this feature avoids waking you up during your deep sleep and finds the best time 30 minutes before the specific alarm time to wake you up to ensure you wake up refreshed. The update also includes a new Screen Time Out option that allows you to set how long the Fitbit Charge 4 screen lasts after waking up.
Generally, this new update carries build No. 1.96.29 and can be downloaded through the official Fitbit app.