Comparison

2FA Authenticator (2FAS) vs Proton Calendar

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

Head to head
About

2FA Authenticator (2FAS)

Securely log in to your online accounts with two-factor authentication. This app protects your personal data and passwords from cyber threats with a simple, private, and open-source solution. It offers easy token restoration, app protection, and offline functionality.

Highlights
  • Two-factor authentication
  • Token backup and restore
  • App protection with passcode/biometrics
  • Open-source and transparent
  • Offline functionality
  • Cross-device sync
  • One-tap authentication with browser extensions
Features
Read full description

2FAS is the easiest way to enable two-factor authentication (or multi-factor authentication) to verify your identity and securely log in to accounts to keep your personal data and passwords protected from cyber threats — all from one app, 100% free! The world’s most secure, private, and simple 2FA app. Secure: • Easily restore your tokens with backups. • Add app protection with your passcode or biometrics. • 2FAS is open-source, transparent, and community-driven. Simple: • 2FAS syncs across your mobile devices. • An interface designed for simplicity. • One-tap authentication with 2FAS Browser Extensions. • Multi-language support. • Quick guides for setup and support. Private: • 2FAS works offline. • 2FAS doesn't store any passwords or metadata. • 100% anonymous use, no account required. It’s not too late to protect your data, so what are you waiting for? Protect your online accounts and services now with TOTP and HOTP algorithms. Start using the 2FAS authenticator app today! If you have any questions, talk with us on our Discord server: https://discord.gg/q4cP6qh2g5 Learn more about 2FAS: • Check our GitHub repository: https://github.com/twofas • Visit our website at: https://2fas.com/ • Follow us on X: https://x.com/2FAS_com • Subscribe on YouTube: https://www.youtube.com/@2FAS

About

Proton Calendar

This app helps you manage your schedule with privacy in mind. It offers various viewing options, reminders, and recurring event creation. All your data is protected by end-to-end encryption and strict Swiss privacy laws, ensuring your personal information is not tracked or harvested.

Highlights
  • Agenda and day view
  • View and reply to invites
  • Automatic event addition from email
  • Light and dark mode
  • Multiple reminders
  • Recurring events
  • Cross-device sync
Features
Read full description

A calendar is a record of your life: Proton Calendar helps keep it private. Make the most of your time - See your upcoming events as you like with agenda or day view - View and reply to invites - Events and invites are automatically added to your calendar from your Proton Mail inbox - View your schedule in light or dark mode - Add multiple reminders for your events - Create recurring events on a daily, weekly, monthly, yearly, or custom basis - Keep your calendar in sync across all your devices Private by default - No ads, no trackers, and no data harvesting - We can’t spy on your calendar or misuse your data - Protected by the same end-to-end encryption used in Proton Mail - Event names, descriptions, and participants are stored with zero-access encryption - Based in Switzerland, all your data is protected by strict Swiss privacy laws People before profits - Funded by users, not advertisers — Privacy is our business model - Built by scientists and engineers who met at CERN and MIT and founded Proton Mail - Used by high-profile journalists and organizations globally What others say about Proton: “Proton has now made it stupid-easy to encrypt your schedule. Information about what you plan to do, where, and with whom, can be just as sensitive as the messages you send and receive.” Gizmodo Follow Proton on social media for all the latest news and offers: Facebook: /proton Twitter/X: @protonprivacy Reddit: /protonmail Instagram: /protonprivacy EULA: http://www.apple.com/legal/itunes/appstore/dev/stdeula

Screenshots

2FA Authenticator (2FAS)4 screens
Proton Calendar4 screens

Verdict

The call

The clearest difference is rating: 2FA Authenticator (2FAS) at 4.7 against Proton Calendar's 4.1. 2FA Authenticator (2FAS) also leads on review sentiment (77% vs 41%) and in-app purchases (none vs 2). Proton Calendar's advantage is iOS requirement (16.0 vs 18.6). On price, update cadence, ads and monetization model 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. Proton Calendar sells 2 one-off in-app purchases. 2FA Authenticator (2FAS) asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

2FA Authenticator (2FAS) holds the better App Store score, 4.7 against 4.1. That said, the two scores are not equally well evidenced: 2FA Authenticator (2FAS) has 36K ratings behind it against 1.6K, so its average is the more settled of the two. Written reviews point the same way: 77% of 2FA Authenticator (2FAS)'s written reviews are positive against 41% of Proton Calendar's.

UpkeepUpdate frequency

2FA Authenticator (2FAS) ships an update monthly, Proton Calendar every 5 weeks. The most recent releases landed on October 29, 2026 and October 28, 2026 respectively.

Scorecard5 real differences · 5 level
2FA Authenticator (2FAS) versus Proton Calendar: the parameters behind the verdict, then further details
Parameter2FA Authenticator (2FAS)Proton Calendar
PriceFreeFree
Rating4.7 (36K ratings) — better4.1 (1.6K ratings)
Positive reviews77.3% of reviews — better40.7% of reviews
Number of ratings36K — better1.6K
Update frequencyMonthly — betterEvery 5 weeks
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFreeFree
DevicesiPhone, iPad, Apple Watch — betteriPhone, iPad
Requires iOS18.616.0 — better
Further details — not scored
Size81 MB185 MB
Age rating4+4+
DeveloperTwo Factor Authentication Service Inc.Proton AG

Customer experience

2FA Authenticator (2FAS)

All ratings35,640 ratings
Positive93.1%
Neutral2.1%
Negative4.8%
Written reviews724 reviews
Positive77.3%
Neutral5.4%
Negative17.3%

Proton Calendar

All ratings1,415 ratings
Positive71.1%
Neutral13.7%
Negative15.2%
Written reviews641 reviews
Positive40.7%
Neutral26.4%
Negative32.9%

User reviews

2FA Authenticator (2FAS)

From 36K App Store ratings

What we love

  • 🚀 Efficient and fast
  • 🔒 Secure and private
  • 👍 Simple and intuitive UI
  • 💡 Customizable icons and folders
  • 🔒 iCloud backup and sync

Room to improve

  • 🐛 Occasional bugs and crashes
  • 🔒 Lack of password/PIN protection
  • 🕰 No Apple Watch app
  • 🐛 Issues with push notifications
  • 🕰 Missing desktop/web app

Proton Calendar

From 1.6K App Store ratings

What we love

  • 🚀 Intuitive interface
  • 🔒 Secure and private
  • 👍 Good integration with Proton suite
  • 👍 Visually appealing design

Room to improve

  • 🐛 Slow performance and crashes
  • 🔍 Lacking search functionality
  • 📅 Missing advanced calendar views (week, month)
  • 🔗 Limited integration with other calendars

Bugs and requests

2FA Authenticator (2FAS)

Reported bugs

3 issues
  • Tokens disappearing after device changes
  • Push notification failures
  • Incompatibility with older devices

Requested features

5 requests
  • Alphanumeric passcode option
  • Custom icon uploads
  • Apple Watch app
  • Desktop/web app
  • Improved support and communication

Proton Calendar

Reported bugs

3 issues
  • Issues with time zone settings
  • Notifications not working reliably
  • Inability to edit shared events

Requested features

5 requests
  • Widgets for quick access
  • Ability to invite and share calendars with others
  • Support for importing/exporting calendar data
  • Customization options (colors, alerts, etc.)
  • iPad-optimized version

In-app purchases

None

2FA Authenticator (2FAS)

No in-app purchases

2 purchases

Proton Calendar

One-time2
  • Mail Plus (1 year)$59.99
  • Proton Unlimited$149.99

Questions

Is 2FA Authenticator (2FAS) free?
2FA Authenticator (2FAS) is free to download, with no in-app purchases.
Is Proton Calendar free?
Proton Calendar is free to download, with in-app purchases available.
Which has better reviews, 2FA Authenticator (2FAS) or Proton Calendar?
2FA Authenticator (2FAS) is rated higher. 2FA Authenticator (2FAS) averages 4.7 out of 5 from 36K ratings, while Proton Calendar averages 4.1 from 1.6K ratings.
Do 2FA Authenticator (2FAS) or Proton Calendar have ads?
Neither 2FA Authenticator (2FAS) nor Proton Calendar shows ads.
Which is updated more often, 2FA Authenticator (2FAS) or Proton Calendar?
2FA Authenticator (2FAS) ships an update monthly, and Proton Calendar every 5 weeks. Most recently, 2FA Authenticator (2FAS) was updated on October 29, 2026 and Proton Calendar on October 28, 2026.

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