Plugin that adds buttons to the Visual Editor?

Hello! I’ve been searching the plugin directory but I couldn’t find anything that does what I want.

In my blog entries, I’d love to be able to add <h2></h2> or other size headings with one click like I can with strong and emphasis and all the rest. Right now I just click over to the code editor and add it in manually but it slows down the process, especially for longer articles with a lot of headings to find.

Is there a plugin that exists that will allow extra buttons on the visual editor? Or is there some way without a plugin to do this easily?

Thank you for your advice!