CallMerlin vs FollowUpThen

CallMerlin describes itself as an AI Chief of Staff that connects to business systems and can be used through phone, chat, widget, desktop, mobile, Slack and Teams. Its workflows can span multiple systems, respond to triggers and include an analysis step with auto-inject. Reads can happen immediately, while writes, emails and payment files wait for approval unless direct execution is enabled. The integrations page lists 96 native deep integrations and says 900+ are available through managed connectors, with examples including HubSpot, Salesforce, Slack, Moneybird, Microsoft 365, Gmail, Stripe, Shopify and Zoom. CallMerlin says each teammate has an individual PIN and permissions are enforced server-side. Credentials use AES-256-GCM encryption, data in transit is protected by TLS, and access uses PIN plus 2FA. Call transcripts and AI summaries are kept for at most 90 days by default; audio is not retained. Starter costs €55/mo (annual), and a 7-day trial is offered; there is no free plan. Android is in closed alpha and the iOS App Store listing is coming soon.

FollowUpThen is an email reminder service that schedules a follow-up when a date or time is placed before its email address. It handles intervals, specific dates, and recurring reminders. Adding it in BCC keeps a reminder private to the sender; adding it in CC sends the due follow-up to everyone in the email's To field. Upcoming reminders can be managed in a web app, by emailing [email protected], or through a daily agenda. The basic reminder workflow does not require inbox access. Listed add-ons include response detection, SMS notifications, persistent tasks, and automatic cancellation when a reply arrives. The service also lists Zapier connections and Google Calendar features. Its free plan allows 50 active follow-ups per month. The Base Plan costs $5 a month, and a 14-day trial is listed. It is available on Android, iOS, and the web; the email-based workflow also works on phones, PCs, and tablets. The service describes encrypted message storage and a privacy mode that deletes message bodies and attachments when a reminder is scheduled.