The phrase "a tool that lets" is correct and usable in written English.
You can use it when describing a tool or software that provides a specific capability or function to the user.
Example: "This software is a tool that lets users easily manage their tasks and deadlines."
Alternatives: "a tool that allows" or "a tool that enables".
In March, Foursquare introduced a tool that lets businesses see who is checking into their locations.
"It provides a tool that lets us tweak the cell and see what happens," says Chen.
A tool that lets developers turn existing software into fully functional browser-based applications is becoming an increasingly popular way to make business applications accessible via the Web.
For even greater political ads transparency, we have also built a tool that lets anyone see all of the ads a page is running.
Jigsaw, the security incubator owned by Google's parent company Alphabet, has just rolled out a tool that lets users bypass sites that are blocked by repressive governments.
Software designer and developer Bret Victor broaches these questions beautifully in a short 35-minute presentation at Stanford...Victor sees the need for a tool that lets scientists and researchers directly and dynamically visualize a wide array of data.
HelloFax, for example, created a tool that let people send their representatives faxes voicing their opinions through the Web.
(One of the features Amazon proudly displayed when it launched its Fire Phone was a tool that let people order from Amazon by taking pictures of items).
The features were added as an update last week, along with other changes like a tool that let people pay to see snaps that had disappeared.
Facebook tried offering Kiwis disappearing messages (in the vein of Snapchat) and a tool that let users pay a small fee to promote their status updates to friends.
That could include a web retailer with a tool that let people recommend music or books to a friend, so the retailer gets a presence among Facebook's rapidly expanding audience and Facebook gets more traffic.
