Hi,
Have installed Google smartapp when I was using classic app. Moved to new application and under smartapps there is no Google anymore. It still can be found from classic app and it can be used to add or remove sensors from ST to Google Home.
Is this known issue or am I missing something?
Click on menu (three bars in the upper left of the screen) then click on settings (the cog icon) and choose Connected Services. Click on the name to open.
Note: don’t swipe left on the name of the service or it will prompt you to delete the integration
Oh master. Thank you for your wisdom. 
The app does show up in connected services, but it does not let you see or change any of the connected devices or routines that were set up in the classic app. It seems very useless!