Runcaster connects to Garmin and coaches from your real data — splits, heart rate, elevation, even the weather you ran in. Chat with your coach to build a training plan, and it adapts after every run: get sick, travel, or blow up on Tuesday, and the week reshuffles. Workouts push to your watch as structured steps. It remembers your goals and injuries between conversations. No watch? Start in chat and connect a Garmin later. 14-day free trial, no credit card. Solo dev/runner in Hoover, Alabama.