These are basic yoga stretching movements that I can do on the mat (on my stomach or back) without worrying too much about balance or the distraction of my active 1 year old. Sometimes he tries to copy the movements; otherwise he just wants to climb on top of dad.
3 rounds of (20-30 seconds holds each pose):
Child's pose (Balasana)
Thread the needle (Parsva balasana)
Cat-cow pose (Chakravakasana)
Happy baby pose (Ananda balasana)