The download button opens the iTunes App Store, where you
may continue the download process. You must have iTunes installed with an
active iTunes account in order to download and install the software. This
download may not be available in some countries.
From Shoo Fly:
Nursery rhymes are a great way to help children develop both their language skills and a love of reading.'Wind the Bobbin' app can be used by parents, carers and families to share nursery rhymes with their children or by any professional organising a rhyme time session.