30日プランクチャレンジ！

A focused core training app built around a 30-day plank challenge. Strengthen your abs, back, and posture at home in minutes a day with guided timers, clear form cues, and smart progress tracking. Ideal for busy users seeking a simple, effective home workout. Keywords include 30-day plank challenge, core workout, home fitness, plank workout app, fitness tracker. Core features - Progressive 30-day plan with auto timers, rest days, and clear form guidance - Personalized levels and reminders to fit beginner, intermediate, or advanced goals - Progress tracking with streaks, charts, and calories estimate to keep you motivated