Plugin Columns adds several columns to the plugins list (Categories, dates, counters). Useful if you have a lot of plugins installed to filter by categories and sort by install date etc.
Add plugins to Categories. Right click (or ctrl/command click) on column headers to access the options (it can also be accessed in the screen options) to create categories. Plugins can be added to categories by clicking the pencil icon in the category column for the plugin or with bulk edit. In the options the categories can be pinned to the plugins menu (click the pin icon next to the category name) and also hidden from the plugins list (only show up in the category list). There is a category filter select at the top of the plugins list, that will only show if categories has been created. Categories can also be filtered by clicking on the category link in the column.
All columns can be sorted by clicking on the columns header, and there is also a sort dropdown list (that will show the column if it’s hidden).
Deleted plugins will be added to a trash list (like posts and pages). From there they can be reinstalled or removed (bulk actions also work).
Plugins and it’s categories can be exported and then imported at another installation. An import list will show the imported plugins and from there they can be installed. The import link will appear at the top links (all, active etc.). This can also be used to backup the categories, since when importing it will add the categories to installed plugins.
The plugin works with multisite installations. The network admin will have more options (import/export and clear), and certain columns like activated will be unique per site. Pinned and hidden categories are also per site.
The update column fetches the dates from the file system (and when a plugin is updated), but the install date will only be added when a plugin is installed. The install date could have been populated with file dates like the updated column, but that would probably be the update date and not the install date since those dates change when plugins are updated. Sorting by install date will show recently installed plugins, and that is it’s intended use, and not seeing historical data.
Counters are an addition to the updated and activated columns to identify plugins that update frequently (or opposite) and plugins that have been activated/deactivated many times. The activated counter is useful when testing plugins compatibility, then it becomes a most popular list.