Tuta Mail vs OSO+
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Tuta Mail
Secure your communications with an encrypted email service offering end-to-end encryption for emails and contacts. Enjoy features like anonymous registration, an ad-free experience, and a free encrypted calendar. Protect your privacy with a service developed and hosted in Germany.
- End-to-end encryption
- Anonymous registration
- Ad-free experience
- Free encrypted calendar
- Quantum-safe encryption
- Open source code
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PROTECT YOUR PRIVACY WITH TUTA MAIL – FREE, SECURE & ENCRYPTED EMAIL Take control of your email with Tuta Mail, the world’s most secure email service, trusted by over 10 million users. With end-to-end encryption, your emails and contacts stay private. Fast, open source, and free: Tuta Mail is built with the highest security standards. WHY CHOOSE TUTA MAIL? Stay Secure • Quantum-Safe Encryption: Your entire mailbox and contacts are fully end-to-end encrypted – only you can access them. • Zero Tracking: We never track or profile you. Your data is yours. • Anonymous Registration: Sign up without providing a phone number or personal details – for free or pay anonymously with cash or cryptocurrency. • Open Source: Our code is publicly available for independent security review. Boost Your Productivity • Free Secure Email: Get a free email address with @tutamail.com, @tutanota.com, @tutanota.de, @tuta.io, or @keemail.me and 1 GB of free storage. • Exclusive Domain: Upgrade to a paid plan to create a short @tuta.com email address. • Auto-Sync: Your emails and contacts sync seamlessly across the app, web, and desktop clients. • Offline Access: Read and manage your encrypted emails even without an internet connection. • Contacts App: Sync your Tuta contacts to your phone. Simple & Intuitive • User-Friendly Interface: Clean, modern design with light and dark mode. • Quick Swipe Gestures: Easily organize emails with swipe-to-archive or swipe-to-trash. • Full-Text Search: Securely search your encrypted emails. • Smart Notifications: Delete or move emails directly from notifications to save time. BONUS: FREE ENCRYPTED CALENDAR APP Your Tuta Mail account includes a free encrypted calendar, giving you the same privacy for scheduling and event management. Stay organized while keeping your data safe. WHO IS BEHIND TUTA MAIL? Freedom fighters committed to protecting freedom of speech and your right to privacy! • Developed & Hosted in Germany: Adheres to strict GDPR data protection laws. • Private by Design: We can’t access your data – secure password reset ensures your privacy. • Secure Transmission: Industry-leading security with TLS, PFS, DMARC, DKIM, DNSSEC, and DANE for safe email delivery. TRUSTED BY SECURITY EXPERTS "Tuta provides an exceptional level of security and privacy... If security is your priority, there’s not much better than Tuta." — TechRadar "Since Tuta is open source and has amazing products in development, I moved my email there." — Journalist Dan Arel "Tuta’s email security is unmatched. Its mobile apps are fast and user-friendly, with fair pricing and a free option." — CyberSynchs JOIN MILLIONS WHO TRUST TUTA MAIL Keep Your Email Private: Download Tuta Mail today and join millions who trust us for secure, encrypted communication. Website: https://tuta.com Open Source Code: https://github.com/tutao/tutanota Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula
OSO+
This app acts as an emotional GPS, helping you quickly record and understand your feelings. By practicing emotional awareness, you can improve your communication skills and achieve more harmonious and productive outcomes in personal and professional life. All your data is kept private on your device.
- Emotional awareness tracking
- 3D emotion input (Happiness, Energy, Assuredness)
- Private data storage on device
- Visual information display
- Elegant design
- Improve social and emotional intelligence
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Everything in life is either KRONsense or NONsense. Your heart knows whether something is wasting your time (i.e., NONsense) or adding to your life positively (i.e., KRONsense), and your heart lets you know through the emotions you feel. Practicing emotional awareness is an important life skill. If you find yourself resonating with the above, and you also gravitate toward visualizing information and appreciate elegant design, this is the App for you. How can I conceptualize the OSO+ App? Think of your OSO+ App as your emotional GPS. Why should I use the OSO+ App? In other words, what are the potential benefits? Emotional awareness has gained significant importance in our culture. OSO+ App offers you a super quick and easy way to record how you feel whether you are angry, sad, relaxed, madly in love, and everywhere in between. Use your OSO+ App to focus on your emotion. Studies from Harvard University and other scientifically highly regarded research have shown that having heightened awareness and understanding of one’s own emotion has strong positive correlation with one’s improved ability to communicate in relationships at home and in the professional work place. As you practice frequently and become more aware of your own emotions overtime, your social and emotional intelligence will improve, which will result in more harmonious and productive outcomes for yourself and for the people around you to achieve personal and team goals. How about my data privacy? The OSO+ App is completely private - all your OSOs stay on your iPhone under the protective shield of Apple’s security systems. Where does the name OSO come from? Our app and technology is affectionately named OSO, meaning bear in Spanish and pays tribute to Cloudbear - our Great Pyrenees and beloved family member - known for his boundless love and vigilance against predators. Cloudbear's mission to passionately love and protect deeply inspires us. Our Spanish speaking friends and strangers alike call Cloudbear “oso” given his striking resemblance to a polar bear. What is the technology behind the OSO+ App? The OSO+ App is powered by the new and proprietary OSO-Pearl technology from the KRONxArc / Nectelier Team. How does the OSO-Pearl Technology work? Touch the OSO-Pearl interactive area to record your emotion in 3 dimensions: x, y, and z, for happiness (H), energy (E), and assuredness (A), respectively. For example, if you feel happy, your OSO Mark would be on the right half of the OSO-Pearl because that's the "+" side of the x-axis; if you feel your energy is elevated, your OSO Mark would be on the top half of the OSO-Pearl because that's the "+" side of the y-axis; if you're very sure about how you feel, tap multiple times to mark your OSO to express your certainty - this increases your assuredness which is the z-axis value. What is the lexicon of the OSO+ App? When using the OSO+ App, we think of the word 'OSO' as a noun, verb, or an adjective. For example, capturing an emotion with the OSO+ App can be described as creating an OSO. The action of engaging with the App is called OSO-ing. The OSO also refers to the interactive area that resembles a pearl. Your creation, i.e., the OSO-Pearl with the "OSO Mark" that you'll have marked is called your OSO. Imagine thinking or asking "How's your OSO?" as a way to show you care. When a topic or subject (words, phrase, image, etc.) has been OSO'ed by someone, it shows this subject is worthy of being OSO'ed and worthy of the user's time and efforts. Where can I find App Terms of Use, Privacy Policy, Tutorials and more? We follow the Apple standard Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Check out our website http://www.kronarc.com/oso for more as well as links to a number of "How's Your OSO" video tutorials. How can I reach the OSO+ App team? User requests and feedbacks are our priority - reach us via support@kronarc.com Time to start OSO-ing, enjoy!
Screenshots
Verdict
The clearest difference is price: Tuta Mail at Free against OSO+'s $19.99. Tuta Mail also leads on update cadence (weekly vs every 2 months) and ratings volume (3.8K vs 6). OSO+'s advantage is review sentiment (100% vs 65%) and rating (5.0 vs 4.7). On ads, in-app purchases, monetization model 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
Tuta Mail is free to download; OSO+ costs $19.99 up front. Tuta Mail sells 4 in-app purchases, starting at $3.99 per month and OSO+ sells 2 in-app purchases, starting at $9.99 per month. Whichever you choose, the download price is not the number that matters.
OSO+ holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Tuta Mail has 3.8K ratings behind it against 6, so its average is the more settled of the two. Written reviews point the same way: 65% of Tuta Mail's written reviews are positive against 100% of OSO+'s.
Tuta Mail ships an update weekly, OSO+ every 2 months. The most recent releases landed on November 3, 2026 and October 24, 2026 respectively.
| Parameter | Tuta Mail | OSO+ |
|---|---|---|
| Price | Free — better | $19.99 |
| Rating | 4.7 (3.8K ratings) | 5.0 (6 ratings) — better |
| Positive reviews | 65.3% of reviews | 100.0% of reviews — better |
| Number of ratings | 3.8K — better | 6 |
| Update frequency | Weekly — better | Every 2 months |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Freemium | Free with in-app purchases |
| Devices | iPhone, iPad | iPhone, Apple Watch |
| Requires iOS | 16.0 — better | 16.2 |
| Further details — not scored | ||
| Size | 85 MB | 164 MB |
| Age rating | 4+ | 4+ |
| Developer | Tutao GmbH | Nectelier Inc. |
Customer experience
Tuta Mail
OSO+
Bugs and requests
Tuta Mail
Reported bugs
4 issues- Login credentials not working
- Accounts being locked or deleted unexpectedly
- Inability to restore deleted accounts
- Syncing issues between devices
Requested features
6 requests- Pinch-to-zoom functionality
- Improved email organization tools (labels, folders, etc.)
- Offline access mode
- Ability to set custom notification sounds
- Separate app for calendar and contacts
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- PGP encryption support
OSO+
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Tuta Mail
- Revolutionary (Monthly)$3.991 Month
- Legend (Monthly)$9.991 Month
- Revolutionary (Yearly)$39.991 Year
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- Legend (Yearly)$99.991 Year
OSO+
- OSO Premium Monthly Membership$9.991 Month
- OSO Premium Yearly Membership$83.001 Year








