Fisher Price Precious Planet projecter mobile
https://www.amazon.co.uk/gp/aw/d/B0...de=asn&creative=22218&creativeASIN=B001GQ2SA2
At £50+ it's pricey for a mobile but LO absolutely loves it. We first put it on for her during playtime at 4 weeks, then when she moved to her cot at 6 weeks, we switched it on for her every bedtime and she just lies there watching the animals go round and smiles and coos till she falls asleep. Recently she has begun to turn her head to the main unit where the music comes from and smile at that and touch it.
Totally worth the money as it saves us from rocking her to sleep at night