How to build a focus timer with AI

There are roughly 200-300 focus timer apps on the market (Pomodoro variants, Forest, Be Focused, Focus@Will, etc.), but fewer than 20 meaningfully integrate AI for personalization. The common failures are: timers that set static intervals without learning your rhythm, AI features that feel bolted-on with zero practical value, and poor data integration with your actual work (calendar, Slack, email). The real gap sits at the intersection of behavioral AI (learning *when* and *how* you focus best) and adaptive scheduling—most tools predict nothing; they just measure. A new vibecoder entering this space should focus on one specific problem: AI that watches your focus patterns across 2-3 weeks, then automatically suggests optimal timer lengths, break timing, and distraction-blocking rules personalized to your energy curve. Don't chase cross-platform; nail the core: learning engine + predictive recommendations + minimal friction. The market is growing (focus tools saw 40%+ growth 2022-2024), but mostly horizontal expansion, not vertical depth. The vibes are shifting toward *intelligent* productivity, not just *tracked* productivity.