The Collins Bird Guide – The Ultimate Field Guide for Britain & Europe app for iOS is on sale in the App Store. Reguarly priced at $17.99, you can download the app today for just $10.99. This is a well-reviewed app based on the best-selling and highly-rated European field guide Collins Bird Guide. Save almost 60% on the app today. This appears to be an unannounced sale that could end at any time — so act fast before the prices goes back up!