You should run the Apple AirPort Utility app for about 60 seconds so it can collect enough data (but NOT more than 90 seconds as that will be too much data) to create an survey file as output.
We are NOT aware of any open sourced iOS app that will tell you the mac address of access points around you.
Open the AirPort Utility app. If prompted select Allow.
Tap on the button and then tap on the button to start scanning.
AirPort Utility scans all available bands at four-second intervals. The scan duration can be changed by moving the slider. Please change the slider to 60 seconds (the default is Continuous)
File Export
After the scanning has stopped, the result can be exported to a local storage or to iCloud by pressing on the button (the exported file is in .txt format)