It’s a problem you may be familiar with, especially if you’re the designated “tech support” contact for your family, office, or group of friends: Someone gets in touch wanting help with a problem on their phone, but you’re not actually with them to take a look.

Troubleshooting issues over an audio call or via text message is typically an exercise in frustration. Just trying to work out exactly what is (and isn’t) happening on screen is a challenge in itself, and that’s before you even get to the stage of thinking about what the underlying causes might be.

The answer is to get the person you’re helping to share their device’s screen with you. Not only can you see for yourself what’s happening, you can also try and fix the problem yourself remotely, over the web.

You’ve actually got more options in terms of apps and approaches than you might think, but one app in particular does the job very well and for free: TeamViewer QuickSupport. If you need something else as well as, or instead of, this, we’ve also mentioned some alternative strategies you can consider.

It almost goes without saying, but exercise caution when using these tools—you don’t want to grant full access to your smartphone to anyone you don’t trust, even if you can cut the connection at any time.

TeamViewer QuickSupport

TeamViewer QuickSupport is by no means the only piece of software that lets you view and control a smartphone screen remotely, but it’s one of the best that we’ve come across. It’s easy to make sense of, it’s free for noncommercial use, and you can download it for both Android and iOS devices.

The person you’re helping needs to have the QuickSupport app installed, so you might need to give them a hand with this first. For the person doing the fixing (which is you), you need the full version of TeamViewer Remote Control for Android, iOS, or desktop, or you need to head to a web browser and type https://start.teamviewer.com into the address bar.