You can get all kinds of Chrome extensions and add-ons for Gmail that make inbox management and utility easier, but some of them are less useful than others. Before you waste space (and potentially money), let’s go over some cheap ones that are actually helpful.

Useful Gmail add-ons you actually need Checker Plus for Gmail works with your Google Calendar, allowing you to schedule and edit events without ever having to open Calendar. It also has a feature that will read your emails out loud to you, which is cool enough on its own to make it a worthwhile download. Plus, it’s free.Grammarly catches spelling mistakes, but regular old Gmail does that, too. What makes Grammarly most useful is its ability to check for errors in grammar, style, and even tone. If you even so much as type a vague, over-used word, Grammarly will pop in and suggest a more precise synonym. This one is free, too.Mailtrack tells you if your email was opened by your recipient. Plus, you can filter your messages by whether they’ve been read or not, so you can stay on top of the ones that haven’t and figure out why, exactly, they’re not being opened. You get link tracking and pop-ups that show you real-time read receipts, but if you use the free version, your emails will say they were “sent with Mailtrack” and you won’t have access to all the features. A pro membership is $4.99 per month. WiseStamp makes it easy to design and use a personalized email signature, which is helpful if you don’t have stunning design skills or simply don’t have the time to whip one up. It’s also free. RingCentral does something cool that you’d think you’d already be able to do natively: It allows you to easily call or text someone from within any Google app where you can see their contact, like within an email. DocuSign eSignature makes the list because it lets you sign documents without leaving Gmail, but it’s only helpful if you find yourself having to sign things a lot. It even lets you sign docs on your mobile devices. It does cost quite a bit, though: For $10 per month, you can send five signatures, but if you want to send unlimited signatures over a month, it costs $25. The Gmail add-ons that are less useful

It can be easy to get carried away with adding every extension you come across to your browser to maximize productivity, but some of them don’t do much more than Gmail already does on its own. For instance, Boomerang is an add-on that lets you schedule when your emails get sent—but you can already do that within Gmail.

The apps you use for work also almost certainly have Gmail add-ons. Zoom and Slack do, for example. The Zoom add-on lets you start a video chat straight from an email, but the same thing is possible if someone simply sends you a Zoom link. The Slack add-on allows you to move entire emails and attachments into Slack, which is useful in its own way, but probably won’t save a lot of time in the long run. Dropbox, Trello, Asana, and Todoist have their own add-ons, too, that enable you to use the apps’ features within Gmail, but these are only helpful if you’re already a hardcore user of those apps. If not, they’ll waste space.

Unless you really rely on an app to get your work done, stick to Gmail add-ons that provide unique features that don’t depend on a third-party system to work—and don’t just replicate the functions Gmail already has.