This watchface has been tested using Pebble firmware version 2.8.1, with no apparent issues - the watchface should work fine for all Pebble "smart" watches running Pebble firmware version 2.x or higher, however no guarantee of successful use can be given for users running Pebble "smart" watch firmware older than this... This watchface was created with Paul Rode's Watchface Generator: http://www.watchface-generator.de Check out Paul's site, create and publish your own watchfaces - if you find his site valuable, I highly encourage you to donate via the applicable link on his Web site.