Comparison

Zulip vs IO Mail

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

Head to head
About

Zulip

This app provides organized team chat for groups of any size, enabling users to read and respond to messages in context. It helps maintain focus by allowing users to catch up on topics of interest at their own pace. The application is open-source and available as a cloud service or self-hosted solution.

Highlights
  • Organized team chat
  • Contextual message reading
  • Topic-based conversations
  • Focus maintenance
  • Open-source software
  • Cloud and self-hosted options
Features
Read full description

Zulip (https://zulip.com/) helps teams of all sizes be more productive together, from a few friends hacking on a new idea, to globally distributed organizations with hundreds of people tackling the world's hardest problems. Unlike other chat apps, Zulip lets you read and respond to every message in context, no matter when it was sent. Maintain your focus and then catch up on your own time, reading the topics you care about, and skimming or skipping the rest. Like everything Zulip, this official Zulip mobile app is 100% open-source software: https://github.com/zulip/zulip-flutter . Thank you to the hundreds of contributors who have made Zulip what it is! Zulip is available as a managed cloud service or a self-hosted solution. Please send questions, comments, and bug reports to support@zulip.com, or tweet @zulip.

About

IO Mail

Features
Read full description

IO Mail is an email app you don't just read — you manage your mail with it. MAIL HUB Every launch starts with a summary of your day: unread mail, messages from important people, today's tasks, overdue items, follow-ups awaiting a reply and snoozed mail, all on one screen. MULTIPLE ACCOUNTS Bring Iyonosfer, Gmail, Outlook and any IMAP account into one app. See all inboxes together and give each account its own color and signature. RULES Create rules by sender, subject, attachment or size: move to a folder, label, flag, mark as read, mute notifications, notify with priority or create a task automatically. For Iyonosfer accounts rules also run on the server, so unwanted notifications never reach your phone. FOLLOW-UPS AND EXPECTED MAIL Get reminded when a mail you sent goes unanswered. Expecting a message? Create an expectation; it's marked when the mail arrives and you're alerted if it doesn't. TASKS, NOTES, SNOOZE Turn a mail into a task with a due date and add it to your calendar. Take notes and send them as mail. Snooze a message and it returns to your inbox when the time comes. LABELS AND IMPORTANT PEOPLE Group mail with colored labels. Mark important people so their mail stands out in Mail Hub. Send unwanted senders straight to junk. CALENDAR INVITATIONS Accept or decline meeting invitations and add them to your device calendar. INSTANT NOTIFICATIONS New-mail notifications arrive within seconds for Iyonosfer accounts. Other accounts are checked in the background at regular intervals. BUILT FOR IPAD In landscape, folders, the message list and the message sit side by side. PRIVACY AND SECURITY No ads, no tracking. Passwords are kept in the device's secure storage and mail content stays on your device. Lock the app with Face ID. Remote images never load without your permission. IO Mail is developed by Iyonosfer Yazılım Hizmetleri.

Screenshots

Zulip3 screens
IO Mail4 screens

Verdict

The call

The clearest difference is update cadence: IO Mail at daily against Zulip's monthly. On price, ads, in-app purchases 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. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Zulip ships an update monthly, IO Mail daily. The most recent releases landed on October 16, 2026 and October 15, 2026 respectively.

Scorecard1 real difference · 9 level
Zulip versus IO Mail: the parameters behind the verdict, then further details
ParameterZulipIO Mail
PriceFreeFree
Rating3.7 (16 ratings) — better—
Positive reviews39.3% of reviews—
Number of ratings16 — better—
Update frequencyMonthlyDaily — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.015.0
Further details — not scored
Size44 MB33 MB
Age rating12+4+
DeveloperKandra Labs, Inc.Ali Kemal Celebioglu

In-app purchases

None

Zulip

No in-app purchases

None

IO Mail

No in-app purchases

Questions

Is Zulip free?
Zulip is free to download, with no in-app purchases.
Is IO Mail free?
IO Mail is free to download, with no in-app purchases.
Do Zulip or IO Mail have ads?
Neither Zulip nor IO Mail shows ads.
Which is updated more often, Zulip or IO Mail?
Zulip ships an update monthly, and IO Mail daily. Most recently, Zulip was updated on October 16, 2026 and IO Mail on October 15, 2026.

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