The MLB The Show Companion App serves as a secondary interface for PlayStation's premier baseball simulation franchise, designed to provide persistent access to game systems outside the primary console experience. This application positions itself as an essential tool for dedicated players who engage extensively with Diamond Dynasty and Road to the Show modes, bridging the gap between limited play sessions and continuous progression systems. The application's core functionality revolves around three primary pillars: marketplace management, squad customization, and progression tracking. Users can execute complex marketplace operations including card searches, buy/sell order creation, and watchlist management with full access to card statistics and market trends. Squad management tools permit comprehensive lineup adjustments, rotation changes, and captain assignments, while progression systems display detailed XP Reward Path advancement, Team Affinity missions, and collection/exchange requirements. The Face Scan feature attempts to translate mobile camera capture into in-game player models, though implementation appears inconsistent across devices. User experience varies significantly based on device compatibility and server connectivity. The interface follows console design patterns with adapted touch controls, presenting dense information through tabbed navigation. Real-world usage patterns show peak engagement during marketplace fluctuations and between gameplay sessions, with users frequently checking order statuses or making quick lineup adjustments during downtime. Performance depends heavily on stable internet connectivity, with offline functionality being virtually nonexistent beyond cached data viewing. User feedback reveals polarized experiences, with technical issues dominating negative impressions while functional stability receives praise when operational. Multiple reviews from April and May 2025 (AlexKouyoumjian, Usernamenottaken12345) indicate recent improvements in core functionality, describing the current version as 'incredibly' effective for marketplace and squad management. However, persistent technical problems remain evident, with wdcwdcaa (May 2025) reporting complete login failure and Clemen the lemon (June 2025) noting Face Scan functionality failures despite current app versions. These reports suggest ongoing stability challenges particularly around authentication and hardware-dependent features. The application delivers substantial value when operational, particularly for players engaged with Diamond Dynasty's economy and progression systems. Its strengths lie in comprehensive marketplace control and squad management capabilities that effectively extend gameplay beyond console sessions. However, persistent technical issues regarding authentication and feature-specific functionality (particularly Face Scan) create inconsistent user experiences. The app serves most effectively as a supplemental tool for committed players rather than a standalone experience, with value directly proportional to user engagement with MLB The Show's live service elements.