I using phpDesigner IDE to develop this application, so you should also use it and add project with root to script root folder.
You can find which file to edit based by URL:
For everything with “_m” extension (models):
If you want to find HTML file in admin, you can search in applications/views/admin, check out this:
Frontend template files are located in folder templates/{your-template}/
Technical documentation is available in: http://real-estate.iwinter.com.hr/documentation/#!/templates
And some basic finding guide: http://iwinter.com.hr/support/?p=5891