Hello Lech,
There are 2 files you must edit to disable the popup and hover effect.
Comment out line 19 of the enqueue.php file located on /inc/ folder.
https://www.dropbox.com/s/9i4y3iisdo6ova1/integral%20disable%20pretty%20photo.PNG?dl=0
Remove the css classes from the project_grid_widget.php file located in /inc/widgets/ folder,
https://www.dropbox.com/s/1w74n2wd5ox9yfd/integral-grid-widget-hover.PNG?dl=0
