Hi, while checking for compatibility with PHP 7, found this:

FILE: /var/www/site.com/public_html/wp-content/plugins/wordpress-popular-posts/wordpress-popular-posts.php
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FOUND 0 ERRORS AND 24 WARNINGS AFFECTING 24 LINES
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  895 | WARNING | Method name "WordPressPopularPosts::__activate" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
  951 | WARNING | Method name "WordPressPopularPosts::__deactivate" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
  983 | WARNING | Method name "WordPressPopularPosts::__upgrade" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 1048 | WARNING | Method name "WordPressPopularPosts::__do_db_tables" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 1095 | WARNING | Method name "WordPressPopularPosts::__check_requirements" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 1404 | WARNING | Method name "WordPressPopularPosts::__flush_transients" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 1425 | WARNING | Method name "WordPressPopularPosts::__update_views" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 1783 | WARNING | Method name "WordPressPopularPosts::__get_popular_posts" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 1901 | WARNING | Method name "WordPressPopularPosts::__render_popular_post" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 1982 | WARNING | Method name "WordPressPopularPosts::__cache" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 2461 | WARNING | Method name "WordPressPopularPosts::__get_img" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 2523 | WARNING | Method name "WordPressPopularPosts::__image_resize" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 2555 | WARNING | Method name "WordPressPopularPosts::__get_image_file_paths" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 2666 | WARNING | Method name "WordPressPopularPosts::__get_attachment_id" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 2702 | WARNING | Method name "WordPressPopularPosts::__fetch_external_image" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 2993 | WARNING | Method name "WordPressPopularPosts::__format_content" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 3114 | WARNING | Method name "WordPressPopularPosts::__get_image_sizes" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 3186 | WARNING | Method name "WordPressPopularPosts::__is_numeric" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 3196 | WARNING | Method name "WordPressPopularPosts::__curdate" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 3206 | WARNING | Method name "WordPressPopularPosts::__now" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 3216 | WARNING | Method name "WordPressPopularPosts::__microtime_float" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 3234 | WARNING | Method name "WordPressPopularPosts::__merge_array_r" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 3257 | WARNING | Method name "WordPressPopularPosts::__is_bot" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
 3281 | WARNING | Method name "WordPressPopularPosts::__debug" is discouraged; PHP has reserved all method names with a double underscore prefix for future use
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