A few bugs I've seen
Samsung S9, Android 9.0, Cronometer app version 2.1.8
When you go to Profile / Connect Devices, the User Interface does not have an "exit" indicator anywhere, which means you have to use the native Android "back" button to get back to the main page. This isn't a big deal, but the problem is that sometimes after you add a new device, when you click the Android back button, it actually closes the entire app. I can't reproduce this problem reliably though.
Sometimes when I click forward to a future day to input details of what I think I'm going to eat (or more likely as most people that I know do, you use it as a scratch pad to see what foods you might want to eat that will meet your targets for that day), I get a blank black screen and have to force close the app. This doesn't happen consistently either, just every once in a while.
(edit 3/28 - added in device, OS, and app version info)