The app now supports watchOS 4 and can potentially have a complication, however in testing the complications have a very small CPU and network budget, so it can only update a few times per hour, then it gets stuck on the last update. This makes it show the wrong prediction for a while. I’m looking into ways around it to reduce the CPU and network, but it is a fundamental issue with the way complications work in watchOS.Dermot supported this idea ·Dermot commented
With WatchOS 3, this should now be possible. Any apps with complications remain in memory and can update in the background.