Yookidoo baby gyms and play mats give your baby one home base from their first weeks through sitting up on their own. Rather than a static arch your baby outgrows by three months, each Gymotion gym converts across four play positions — back play, tummy time, sitting, and napping — with moving toys, layered textures, sounds, and high-contrast colors that hold a newborn's attention long past the first look. Twelve gyms and mats, from $39.95.