My name is Zoltan Pallagi, and I’m just an android developer who likes creating useful Android based applications.
WiFi Analyzer is free (and always will be), but you can donate my work via buying the professional version or if you need the special features provided by the Pro version.
 
You can find more useful application created by me on AndroidUtils: https://androidutils.io
Or on Google Play:
 
The most popular ones: