The following is the latest firmware for each scale:
To check your firmware:
With your scale powered off, press and hold the power button. When "SEt" displays, release the power button and the number that flashes after is your firmware version.
To update your firmware, go to your device's app store and select the Acaia Updater app for you specific scale.
Here is an example of checking the Lunar's firmware:
Previous Lunar firmware:
Previous Pearl firmware: