SC Back in Stock Notify Me

I have had the SC Back in Stock app for years now. I've only recently had an issue and I don't believe that is the app itself but my theme which is from 2018. I've always had the $5 plan. Other than not being able to really brand the emails (which I understand based on only paying $5 a month) I've never had an issue. I just reached out to the developer on the chat within the app and it is 8:30am EST on a Sunday, of a holiday weekend and I got a reply in the chat immediately! Again, this issue is not their fault but they immediately got into action and I'm just waiting on their final reply. This app has probably been one of the most reliable apps I've had, especially based on that low price point.