Samsung Galaxy Watch5
Hey, considering the Galaxy Watch5 just released a few months ago, the following is totally understandable, but it appears that Cronometer doesn't currently work on the Watch5. You can download and install it fine, from both the watch itself or your phone, but when attempting to launch it on the watch, you get an 'app not found' message.
I have a feeling the team is already aware of this and/or working on updated support, but I wanted to put it out there just in case.