Not long ago Google had a very popular site called Labs where it would put interesting little side projects for its online services. Some of the tools did handy useable tricks and others simply extended an existing feature in more specific or niche ways. Sadly, Google decide to discontinue Labs as a separate entity and many of the fun products were discontinued.
However, the Labs ethos does live on in certain products and happily it's still available in things such as Gmail. To get to the Labs in Gmail go to the Settings cog icon and click on Settings. Across the top you’ll see your account tabs, click on Labs and you’ll see the list of available Labs Tools.
The tools include the ability to add an icon to email from your choice of verified senders, custom keyboard shortcuts allowing you to speed up your email management, to ability to preview Google Docs in messages and much, much more. It’s very simple to add a Labs tool to your inbox as all you have to do is click on Enable, it’ll be ready to use instantly.
You can search through the Labs tools to see if something you need has already been made. Should there be an idea or feature you’d love to see implemented you can click on Suggest a Labs feature at the bottom of the page and if you’re lucky it might just get made.
The thing you must remember when using any of the Labs gadgets is that they may not work quite as expected or advertised and they can change, break or be removed without notice. However, some of the tools really are very useful so take a look and you might just find that feature you were always been looking for.