Surely this solution is still going to fail the walking/train test -- the icon will be on the screen permanently in those situations. The phone will detect mov

Surely this solution is still going to fail the walking/train test -- the icon will be on the screen permanently in those situations. The phone will detect movement, the icon will appear, it'll fade after a few seconds, the movement will be interpreted as the "shake to bring it back", it'll reappear, then fade, and repeat ad nauseum.