This app is a simply audio analyzer.
And, app can sound sweep signal for measurement for speaker etc.
(you are not use bluetooth with this app, please use wired output)
Frequency resolution is 2.6Hz.
And you can select window function and weighted average value.
Please use this app for your speaker etc!
If you have request for this app, Let me know!
I will confirm your request for you.
If this ipnone is not iphoneX/iphone8 or high spec,
App may not work correctly.