Lower the barrier to starting
Instructions should be brief, easy to find and relevant to familiar devices. Visitors should be able to reach a trial without navigating layers of promotional pages.
Keep the person in view
Enjoyment, comfort and willingness matter more than chasing a score. A parent can observe, encourage and help a child stop when needed.
Explain the limits
A camera cannot observe everything, and a single measurement cannot describe an entire growth journey. Those limits should appear alongside the information people use to make decisions.