Refinements to your world-building journey and app interface. - Revisit the stages you have earned while future stages stay locked until you reach them. - Discover special structures, gifts and monuments through normal play. - Updated app information and reliability improvements.

Your world has more to discover. - Uncover a different 24-chapter mystery for each world style through letters that respond to your choices. Mail begins after three qualifying cardio days. - Send letters and gifts to accepted friends. Earn Cardia dollars from synced steps and logged cardio, then browse the Gift Shop with searchable friend selection. - Build a research lab and discover special structures and new gifts. - Join optional cooperative mysteries with friends and work toward shared monuments, one cardio day at a time. - Find your mailbox on its own floating cloud, with a bright glow when unread mail arrives and easier controls. - Improved Apple Health imports, saved progress and daily activity limits. Multiple logs on one date still count as just one cardio day.

- Fixed friend invitation links and improved how invitations survive sign-in and onboarding. New to Cardia World? Install the app, then reopen your invitation to connect. - Your world now shows clearer signs of missed cardio, including damaged structures, neglected scenery and unhappy citizens. Return to cardio to gradually restore it while keeping your earned progress. - Improved sign-in reliability, saved-progress handling, Apple Health workout imports and 3D world stability.