Comparison

Superhuman Mail vs knowb4usign

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Superhuman Mail

This email application streamlines inbox management with AI-powered drafting and summarization. It helps users prioritize important messages, schedule emails for optimal delivery, and collaborate with teams through shared email views and integrated CRM tools. Save time and improve responsiveness with advanced features.

Highlights
  • AI email drafting
  • Automatic email summarization
  • Customizable inbox triage
  • Scheduled email delivery
  • Email sharing and commenting
  • Calendar integration
  • CRM integrations (HubSpot, Salesforce)
Features
Read full description

Superhuman Mail is the most productive email app ever made. Designed to help you fly through your inbox, be more responsive to what matters most, and collaborate faster than ever before, Superhuman Mail helps teams on Gmail and Outlook save 4+ hours per person each week. FLY THROUGH YOUR INBOX 2X FASTER Write better and faster with AI that matches your unique style for each person. Get draft replies on every email that needs a response, ready to edit and send. Turn your thoughts into polished emails in seconds with Write with Voice. Stay a step ahead with an automatic 1-line summary above every conversation. Automate phrases and entire emails with Snippets. BE MORE RESPONSIVE TO WHAT MATTERS MOST Automatically triage incoming email with customizable inbox splits, so you can always focus on what matters most. Avoid the clutter for good with Auto Archive. Never let a follow-up slip, with automatic reminders to reply. Send emails when they're most likely to be opened, so you land at the top of your recipient's inbox at just the right time. COLLABORATE FASTER THAN EVER BEFORE Share a live view of any email, and add comments for your team—no need to repeatedly screenshot, forward, or bcc. See your calendar without leaving your inbox. Get full context on your customers and deals with HubSpot and Salesforce directly integrated. Connect all your Gmail and Outlook accounts to AI tools like Claude and ChatGPT via the Superhuman Mail MCP. Teams save 20 million hours every single year with Superhuman Mail. https://superhuman.com/terms

About

knowb4usign

This app provides plain-English summaries of legal documents like contracts, leases, and terms of service. It breaks down complex clauses, highlights your obligations and rights, and assigns a risk score for quick understanding. Upload or scan documents for an instant AI review.

Highlights
  • Plain-English contract summaries
  • Clause-by-clause breakdown
  • Identification of obligations and rights
  • Risk assessment score
  • Document upload and camera scanning
  • AI-powered review
  • Follow-up question chat
Features
Read full description

Read what you sign. knowb4usign turns any contract, NDA, lease, EULA, or terms-of-service into a plain-English summary you can actually understand. Upload from your phone or scan paper documents with your camera — get a clause-by-clause breakdown in seconds. WHAT YOU GET FOR EVERY CONTRACT • A one-line takeaway in human language • Your concrete obligations — what YOU have to do • Watch-outs and unusual terms (rated Standard, Unusual, or Aggressive) • Rights you retain even after signing • A 0–100 score with a tier label so you know at a glance how the contract reads WORKS ON • Job offers and employment agreements • Apartment leases and real estate contracts • Vendor contracts and SOWs • NDAs and confidentiality agreements • EULAs and software license terms • Terms of service and privacy policies HOW IT WORKS 1. Sign in with Apple, Google, or email 2. Upload a PDF or Word doc — or use your camera to scan paper 3. Get an instant AI review in plain English 4. Ask follow-up questions in chat — "what does this mean if I quit?" PRIVACY FIRST • Sign in with Apple is supported — you can use Hide My Email for full privacy • Documents are analyzed and processed; not used to train AI models • Delete your account anytime from inside the app • Full privacy policy at knowb4usign.com/privacy WHY KNOWB4USIGN Most people skim a 40-page contract because they're tired and the alternative is paying a lawyer to read it. knowb4usign is the in-between. Plain-English review of every clause, in your pocket, available the moment you need it. Free to start — 1 free contract review with no credit card required. Paid plans unlock higher volume and team features. Built by Pexora LLC. Read what you sign.

Screenshots

Superhuman Mail4 screens
knowb4usign4 screens

Verdict

The call

The clearest difference is in-app purchases: knowb4usign at none against Superhuman Mail's 1. knowb4usign also leads on rating (5.0 vs 4.6) and iOS requirement (15.1 vs 26.0). Superhuman Mail's advantage is ratings volume (3.7K vs 1). On price, update cadence, ads and device support there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Superhuman Mail sells 1 in-app purchase, starting at $29.99 per month. knowb4usign asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

knowb4usign holds the better App Store score, 5.0 against 4.6. That said, the two scores are not equally well evidenced: Superhuman Mail has 3.7K ratings behind it against 1, so its average is the more settled of the two.

UpkeepUpdate frequency

Superhuman Mail ships an update weekly, knowb4usign every 2 weeks. The most recent releases landed on September 25, 2026 and September 13, 2026 respectively.

Scorecard5 real differences · 5 level
Superhuman Mail versus knowb4usign: the parameters behind the verdict, then further details
ParameterSuperhuman Mailknowb4usign
PriceFreeFree
Rating4.6 (3.7K ratings)5.0 (1 ratings) — better
Positive reviews41.2% of reviews—
Number of ratings3.7K — better1
Update frequencyWeekly — betterEvery 2 weeks
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS26.015.1 — better
Further details — not scored
Size107 MB23 MB
Age rating12+4+
DeveloperSuperhuman LabsPexora LLC

Bugs and requests

Superhuman Mail

Reported bugs

4 issues
  • Login issues and account activation problems
  • Emails not loading or syncing properly
  • Formatting issues in email threads
  • Crashes and freezes on various devices

Requested features

5 requests
  • Unified inbox for multiple accounts
  • Better calendar integration
  • More customization options
  • Improved mobile app experience
  • Table support in email composition

knowb4usign

Not enough reviews yet to summarise bugs or requests.

In-app purchases

1 purchases

Superhuman Mail

Subscriptions1
  • Monthly Subscription$29.991 Month
None

knowb4usign

No in-app purchases

Questions

Is Superhuman Mail free?
Superhuman Mail is free to download, with in-app purchases available.
Is knowb4usign free?
knowb4usign is free to download, with no in-app purchases.
Which has better reviews, Superhuman Mail or knowb4usign?
knowb4usign is rated higher. Superhuman Mail averages 4.6 out of 5 from 3.7K ratings, while knowb4usign averages 5.0 from 1 ratings.
Do Superhuman Mail or knowb4usign have ads?
Neither Superhuman Mail nor knowb4usign shows ads.
Which is updated more often, Superhuman Mail or knowb4usign?
Superhuman Mail ships an update weekly, and knowb4usign every 2 weeks. Most recently, Superhuman Mail was updated on September 25, 2026 and knowb4usign on September 13, 2026.

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