A PBW file is an app used by Pebble smartwatches that can connect to Android and iOS phones. It contains an app or watchface, which includes configuration information, such as the name, language, fonts, icons, and functions of the app or watchface. PBW files are typically used for customized watchfaces, GPS maps, games, alarms, home automation utilities, mood trackers, and sports notification apps.

PBW files can be downloaded from various third-party sites but are primarily downloaded from the Pebble app store. You can browse for watchfaces and apps and install them directly from the Pebble app on an Android or iOS phone. You can also browse and download watchfaces and apps from Pebble app store site in a browser on a computer. You can download the watchface or app by selecting the it then clicking Download PBW to begin the download of the PBW file. After downloading the file, you can copy the file to an Android device and use the Gadgetbridge "FW/App Installer" to install the PBW file to a connected Pebble smartwatch. NOTE: Pebble first released their smartwatches in July 2013 but later was acquired by Fitbit in 2016. Support for the smartwatches only continued through 2017.