Jeff Miller, a personal trainer with more than 20 years experience in the fitness industry, points out that "text neck" is part of a bigger set of problems that he terms "screen slouch," explaining, "The slouch really starts in the knees, kicks in at the hips, and gets really bad by the time you get to your shoulders and neck." Because text neck, ultimately, affects your entire body, he suggests starting with an exercise that emphasizes proper posture: the good ol' chair squat.
Stand directly in front of a sturdy chair with your feet shoulder-distance apart, your arms at your sides. Keeping your spine straight, your shoulders pulled back, and your chest lifted, press your hips back and bend your knees to sit down in the chair. Tap your butt lightly on the chair, then reverse the movement and stand up, again keeping your core engaged and your spine straight. Perform three sets of six to 10 squats. You can disperse these throughout the day as you see fit.