Make specific App into widget?
If you are asking, can one directly reach the temperature controls without logging into the app, the answer is no.  

Since the app doesn't have activities that can be pulled and placed as widgets. Some apps have, some don't. Quick Shortcut maker is one such app that can reveal activities and place them as shortcuts for quick access. I installed the app in question and it doesn't have any activities, except the main log in
- you will need to search for an app that works and can show activities for you to place as shortcuts, which can be directly accessed or used by automation apps