Google Trends
Checking whether a topic is rising before you write about it
Our verdict: The most flexible planning hub for newsletter writers. The free plan covers solo use.
Editorial calendars, idea banks and sponsor CRMs
Free; Plus $10/seat/mo.
Source: official site
2026-10-18
Disclosure: This vendor runs an affiliate program, so we may earn a commission if you sign up through StackKit in the future. It doesn't affect the verdict. StackKit is independent and not affiliated with Substack Inc. Spot an error? Email hello@stackkit.ink.
Checking whether a topic is rising before you write about it
Building a personal knowledge base of notes, quotes and ideas
Collecting highlights from books and articles to feed your writing
A simple kanban for drafts moving from idea to published
Automating busywork such as logging new posts to a spreadsheet or sending sponsor reminders