Great change for those who want to populate their journal entries with content from the web: Day One has launched their IFTTT channel today, which will let you create all sorts of automated recipes such as saving Instagram pictures to a journal, emailing a new entry to yourself, or logging check-ins from a third-party service.
Much as Day One 2 was criticized for ditching iCloud and Dropbox in lieu of its own sync, integrations like this are always better when the developers can fully control the sync platform they're using. Thanks to Day One Sync and support for multiple journals, you can connect to IFTTT and set your recipes to save data into a dedicated journal separate from your main thoughts (something that bugged me a few years ago with a similar solution).
I've been playing around with the beta of Day One + IFTTT, and it works well. I have recipes to save liked tweets and YouTube videos to an 'Internet' journal, and I'm planning to build more soon. If you use Day One and IFTTT, this is a fantastic addition.