No extra campaign
You already wrote the changelog. The toast is that same entry, on the site they use every day.
Use case
Tell people who are already in the app.
Email misses users who never open it. An in-app changelog toast appears on your product the moment you publish — they click it, read the notes, and keep working.
yourapp.com
v2.4
New release
Dark mode is live
Just now · Click to read
Doesn’t interrupt the first visit
It shows after you publish, in a corner. They can dismiss it. It’s not a modal over onboarding.
Two lines of script
Drop the notifier on marketing or in-app. Corner and theme are dashboard settings, not a redesign.
two lines on your site
Feedif('init', { project: 'your-board' });
Feedif('notifier');// toast when you publish