In the mobile version I could not translate the message received on the map eg: "use two fingers to move .."
I replaced in the file listings_map.php the line:

<script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?v=3&key=<?php echo osc_get_preference('api_key', 'plugin-rad_search'); ?>"></script>
whit:

<script type="text/javascript" src="https://maps.googleapis.com/maps/api/js?v=3&key=<?php echo osc_get_preference('api_key', 'plugin-rad_search'); ?>&language=ro&region=RO"></script>In my case,  ro and RO
Now I have the translation into the desired language.  Maybe, this post will be of necessity to others.

Thanks

@Dan
Thanks for a nice tip

I'm coming back with a supplement.
I found that when publishing a new article using a mobile phone the message received "use two fingers to move .."
was not translated (in my case in Romanian)

I changed in the index.php file, line 693
osc_register_script('radius_map_publish_js', 'https://maps.googleapis.com/maps/api/js?v=3&key=' . osc_get_preference('api_key', 'plugin-rad_search'));whit:
osc_register_script('radius_map_publish_js', 'https://maps.googleapis.com/maps/api/js?v=3&key=' . osc_get_preference('api_key', 'plugin-rad_search') . '&language=ro&region=RO');
Now, the message is translated in Romanian.
Maybe this change will be of interest to others.
Greetings, Dan