I have the 5th edition app, beside high quality songs and calls every species is depicted with the book's pictures plus several photos showing all age classes. Great app!I would be interested in feedback on the app if anyone has used.
The 5th edition appears to be available for £14.31 from amazon.
Kindle version is £9.99
The app is £17.49 - however the app is optimised for on screen use and includes '1000 calls'. Which I guess makes it similar to the Collins Bird Guides app (of which I am a fan) . In addition it says that it will update the app in the future for content - in principle future proofing.