Child trust funds are investment funds for children are also tax free, and can be rolled over into an Isa when they mature on your child's 18th birthday. 
There are two types of child trust funds: cash child trust funds, which are completely tax-free, and share-based child trust funds which, like stocks and shares Isas, have dividends paid to them with 10% tax already deducted. 

Junior Isas replaced child trust funds in November 2011. The total amount you can invest in 2014-15 is £4,000 - this can be all in one type of account or split between a Junior Cash Isas and a Junior Stocks and Shares Isa.

Go further: Junior Isas - find out the best rates available for this childrens' savings account.