Echometers by Wildlife Bioacoustics is a great smartphone extension for recording and identifying bat species.
[ECHO METER TOUCH 2 FOR ANDROID (USB-C)][1]ECHO METER TOUCH 2 FOR ANDROID (USB-C)- $179.00 [Sampling rate-256k]
[ECHO METER TOUCH 2 PRO FOR ANDROID (USB-C)][2]ECHO METER TOUCH 2 PRO FOR ANDROID (USB-C) - $349.00 [Sampling rate up to 384k @16bits]
[ECHO METER TOUCH 2 PRO FOR IOS][3]ECHO METER TOUCH 2 PRO FOR IOS- $349.00 [Sampling rate up to 384k @16bits]
[![enter image description here][4]][4]
You can also use RØDE VideoMic GO for general recording.
[![enter image description here][5]][5]
Image courtesy - www.wildlifeacoustics.com and www.macaulaylibrary.org
[1]: https://www.wildlifeacoustics.com/products/echo-meter-touch-2-android-2
[2]: https://www.wildlifeacoustics.com/products/echo-meter-touch-2-pro-android-2
[3]: https://www.wildlifeacoustics.com/products/echo-meter-touch-2-pro-ios
[4]: https://i.sstatic.net/LXlf9.png
[5]: https://i.sstatic.net/IMILy.png