This is great! Both as a provider of blog functionality and as a comprehensive sample plugin to learn from. Are you planning to use this eventually on discourse.org as well or sticking to WordPress?
When precompiling assets I got this error:
undefined method `recurrence' for Blog::UpdateStackOverflow:Class (NoMethodError)
I’m new to rails, but it seems related to sidekiq. Maybe I need to fix my installation somehow? Don’t need twitter or stackoverflow integration on my blog though, so removed the jobs for now and everything seems to work fine.