Onyx Odds enters a crowded marketplace of sports betting applications with a straightforward proposition: centralized odds comparison across major sportsbooks. The app covers popular North American sports including NFL, NBA, MLB and NHL, plus international soccer leagues and tennis tournaments. Rather than attempting to be an all-in-one betting platform, it focuses specifically on odds aggregation - a practical approach for users who maintain accounts with multiple sportsbooks. The core functionality revolves around live odds tracking with refresh intervals typically between 30-60 seconds. Users can filter by sport, see movement graphs for selected lines, and set basic alerts for when odds reach certain thresholds. The comparison view displays up to four sportsbooks simultaneously, showing both moneyline and spread pricing. Parlay builders include implied probability calculations, though advanced analytics like expected value projections remain limited. Missing are features like historical odds databases or arbitrage opportunity scanners that competing services sometimes offer. During testing across various iOS devices, the app demonstrated reliable performance with minimal crashing, though occasional lag appeared when switching between heavily populated game schedules. The dark-themed interface presents information clearly with adequate spacing, though some users might find the color coding system for odds movement requires brief familiarization. Real-world usage scenarios include quickly checking line movements during pre-game research or monitoring live betting odds while watching games. The absence of integrated news feeds or injury reports means users must supplement with external sources for complete situational analysis. With no published user reviews available, assessment relies on hands-on evaluation and comparable app benchmarks. The 2.45/5 App Store rating suggests possible issues with data accuracy or user experience elements not immediately apparent during testing. Common pain points in this app category typically involve delayed updates during volatile line movements or incomplete sportsbook coverage - areas where potential users should verify current functionality before committing. Onyx Odds delivers adequate basic functionality for casual bettors needing straightforward odds comparison, but falls short of being a comprehensive professional tool. The app's value proposition hinges on its simplicity and focused approach, though the absence of more sophisticated features may limit its appeal to serious bettors. For users primarily interested in quick line shopping across major sportsbooks without unnecessary complexity, it represents a serviceable option despite its unimpressive overall rating.