• by Gavin O'Malley , February 13, 2019

Beyond its simple messaging service, Slack’s greatest asset is arguably its ability to serve as a hub for other workplace apps.

Supporting this strength, the company just released Block Kit Builder and Block Kit -- a UI tool and framework to help developers make sure their apps are running smoothly on its platform.

The idea behind Block Kit is to give developers more control over the hierarchy of their app messaging, while the Block Kit Builder is a prototyping tool for actually designing and coding apps.

Giving the tool and framework their name, the Block Kit is made up of stackable “blocks,” which let developers define the order and appearance of any information delivered through their apps.

The building materials with which developers can now build their Slack apps include a “Section” block, which serves as a container for text; a “Context” app for adding metadata and descriptions; and an “Image” block, which is basically an image container.

Additional blocks include a “Divider” to separate and make messages more readable, and Actions -- interactive components for app’s call to action, including buttons, six drop-down menu types, and a date picker.

The Block Kit Builder was designed to help developers prototype app interactions, select blocks and edit code as they please.

It also offers customizable templates that were built based on common use cases for apps, including approvals or notifications.

The new offering comes as Slack faces growing competition from some formidable rivals.

For example, Microsoft Teams -- which is also a messaging platform for businesses -- grew from 3% in 2016 to 21% in 2018, according to a recent report from Spiceworks.

Just last month, Microsoft began building up Teams features for “first-line workers” -- or those who typically work on their feet and interact directly with customers in retail, hospitality, travel, and other such industries.

For Slack and its rivals, first-line employees represent a huge opportunity for growth.

Indeed, there are roughly 2 billion such workers, worldwide, according to Emma Williams, corporate vice president, Modern Workplace Verticals at Microsoft.