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Right Inbox vs Boomerang for Gmail: catalog facts
Right Inbox	Boomerang for Gmail
Paid Paid plans required for full functionality.	Free Can be added to Gmail for free; the homepage does not list paid tiers.
Browser extension	Browser extension
Combines send-later, reminders, and tracking in a single Gmail extension Used by a large base of professionals as a lightweight Gmail add-on	Send-later scheduling inside Gmail Email reminders
Works only within Gmail, not other webmail or desktop clients Full feature set requires a paid plan	Only works with Gmail and Google Workspace Requires granting access to your Gmail account
Browser extension	Browser extension
Closed source	Closed source
License not stated	License not stated
Not stated if an account is needed	Account needed
Not stated if it works offline	Needs internet
Official website Full listing and sources Checked September 22, 2026	Official website Full listing and sources Checked September 23, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.