We have known that the web servers that support the pebble are going away for a while now. To be fair, Fitbit have done a great job of making it a soft landing, but now finally the Pebble services including the app store has now disappeared. This means that the developer portal and the app store has now gone.
However not all is lost. Rebble have managed to put together as alternative community supported set of services. If you have not already done so head over there and follow the instructions for moving your pebble app across to the new servers.
I have moved myself and it seems to work fine (a big thank you to them). I have also moved my Pebble application wrist-spin across and I have had more downloads and hearts since I did so.