Every app varies in cost, from free, to $1, to $20 or more.
FREE!!
free
Once you buy an app, you can use it as much as you want.
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About one dollar each
depending on your app, some are free though
$99/yr for Itunes
It is free to update the app.
£17.95 from their website.
wood+warter=boat
It's £2.99 on the App Store.