ST-compatible RGBW LED Strip Controller Reviews (2023)

[JDRoberts]

You should use the newest version of the app. The older app, which is called “SmartThings Classic” will be discontinued in a few months.

Here is that announcement:

Announcement | Changes to our Legacy SmartThings Platform

Changes to the Legacy SmartThings Platform The explosive growth of our community and platform over the past few years has been an amazing experience for all of us at SmartThings. We have you to thank for building, innovating and growing with us as we push the envelope to what is possible in the connected home. Today, we wanted to let you know about the next evolution in our journey. We are making some important shifts in our strategy to best position our platform for the future and investing more deeply in improving the stability and security of our platform. With these changes, we will empower a broad ecosystem of developers to integrate and innovate with SmartThings using technologies of their choice. Over the course of the next several months, we plan to focus on the development of a …

And this FAQ explains how to tell which app is which:

FAQ: how to tell which version of the SmartThings mobile app that you have