First, decide which kind of tool you want
A human chief of staff does three things: watches everything, decides what needs you, and prepares the answer. Software splits that job differently.
- Email clients (Superhuman, Shortwave) replace Gmail's interface and make you faster inside it. You still do the work, faster.
- Overlays (Fyxer, Inbox Zero, alfred_, Momo) work on your existing mailbox: they sort, draft and track, and you keep your client.
- Agents (Instinct, Zapia) act across many apps, and sometimes on the open web or the phone. Wider reach, more trust required.
- Single-job assistants (Clara) do one thing, usually scheduling, end to end.
- Built-in AI (Gemini in Gmail) helps when you ask and does nothing in the background.
The comparison
We make Momo, so read our placement of it with that in mind. Prices are from each vendor's own pricing page on 10 October 2026 and change often.
| Tool | Kind | Works with | Price (vendor page) | Who sends |
|---|---|---|---|---|
| Momo | Overlay with tracking | Gmail, Google Calendar | Free in early access; ₹499/mo planned | You, every time |
| alfred_ | Overlay | Gmail, Outlook, IMAP; web and iPhone | From $25/mo annual, $29.99 monthly; 7-day trial | Not stated on pricing page |
| Fyxer | Overlay | Gmail, Outlook | Free tier; Pro $37/mo annual, $49 monthly | You ("you decide what gets sent") |
| Inbox Zero | Overlay, open source | Gmail, Outlook | From $18/mo annual, $20 monthly; self-host option | Not stated |
| Superhuman | Email client plus Gmail add-on | Gmail, Outlook | $25 to $33/user/mo annual | Auto Drafts never auto-sent; optional sending on your behalf |
| Shortwave | Email client | Gmail only | Free plan; Business from $30/seat/mo | You; AI filters can archive or delete automatically |
| Instinct | Agent | Text or call; Google Workspace and more | Not published; private access | Not stated; reported to have sent email without asking |
| Zapia | Agent / life assistant | WhatsApp, Gmail, Calendar, Outlook, Slack | Free; Pro US$9.99/mo | You confirm |
| Clara | Scheduling only | Google, Outlook calendars | $80/mo | Clara, no human in the loop by design |
| Gemini in Gmail | Built-in | Gmail | Workspace Starter ₹270 or Google AI Pro ₹1,950/mo | You |
Sources: momo pricing page; get-alfred.ai/pricing; fyxer.com/pricing; getinboxzero.com/pricing; superhuman.com/plans/mail; shortwave.com/pricing; instinct.com and TechCrunch, 24 August 2026; zapia.com/planes; claralabs.com/pricing; workspace.google.com/pricing and gemini.google/subscriptions. All read 10 October 2026.
Best for each situation
There is no single winner. These are the picks we would make for a friend.
- You live in Outlook: Fyxer or alfred_. Momo does not support Outlook yet.
- You want a faster email client and price is not a concern: Superhuman, or Shortwave if you are Gmail-only.
- You want drafts plus follow-ups, promises, scheduling by email and a morning brief, inside Gmail, at a rupee price: Momo.
- You want an agent that books restaurants and buys things: Instinct, if you can get an invitation and accept its data terms.
- You run your life on WhatsApp in Latin America: Zapia.
- You schedule dozens of external meetings a week and want zero touches: Clara.
- You want to self-host and read the code: Inbox Zero.
- You only need help rewriting the occasional email: Gemini in Gmail is already there if your plan includes it.
Five questions to ask before you connect your inbox
Whichever tool you pick, it will read your email. These are the questions that separate a helpful assistant from a liability.
- 1Can it send an email, cancel a meeting or archive mail without me? If yes, under what rule, and can I turn that off?
- 2Does it train AI models on my email by default? Read the privacy policy, not the homepage.
- 3When I disconnect, is my data deleted, or only access revoked?
- 4Who picks the recipients of a draft: the model or code? A model that chooses recipients can be talked into adding one.
- 5What happens when an email tries to give it instructions? Ask the vendor how prompt injection is handled.
Where Momo fits
Momo is an overlay for Gmail and Google Calendar that does the tracking work a chief of staff would: who is waiting on you, who owes you, what you promised, what is on today. It writes the reply in your voice and books the meeting, and it stops at the send button every time. It is free during early access.