"aSleep"
For naptime, the aSleep kids app comes with a timer and a selection of 15 lullabies. If music is a little too stimulating, download the WhiteNoise application to hear ambient noise like an oscillating fan, an airplane or a heavy rainstorm. Select the noises you want, adjust the volume and set a shutoff timer. (Asleep Kids $.99/Whitenoise $1.99)