Plugin to show notification if there are new contents on the river

I have found a plugin that updates the river automatically (using AJAX). But I don't use this plugin because it will make river be flooded of new content.

I want a plugin that show just a text, maybe like "there are 3 new content on the river" and the text is placed above the river, and when we click it, the river will be refreshed.

Is there any plugin like that?