Comparison

Celeris vs Codex AI

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

Head to head
About

Celeris

Enhance your reading speed and comprehension with a word-by-word visual presentation. Import your own content, customize your reading experience, and track your progress to become a more efficient reader.

Highlights
  • Rapid Serial Visual Presentation (RSVP)
  • Coasting mode with gliding lines
  • Import EPUB, plain text, and web articles
  • Automatic progress saving
  • Customizable reading speed up to 1000 WPM
  • Personalizable themes and fonts
  • Reading statistics and progress tracking
Features
Read full description

Read faster without skimming. Celeris uses RSVP (Rapid Serial Visual Presentation) to flash one word at a time in a fixed spot on screen, so your eyes never waste time scanning across lines. The result: you move through books and articles noticeably faster, with your focus locked in one place. Bring your own reading. Import EPUB and plain-text files, or paste in any web article and Celeris converts it into a clean, distraction-free read. The fastest way in is the share sheet — tap Share on a book or link in any app and send it straight to your Library. TWO WAYS TO READ • RSVP — a single word at a time in a fixed focus point, with a color-highlighted anchor letter to keep your eyes locked on. The fastest way to read. • Coasting — several lines glide gently upward past a highlighted focus line, auto-advancing at your pace. More context per glance when you want it. Switch between the two instantly from Quick Settings, without leaving your book. BUILT FOR REAL READING • Never lose your place — your position is saved automatically in every book. • Tap any word to jump straight to it, rewind 10 words, or restart the paragraph. • Jump to any chapter from the Table of Contents. • Highlight passages with a long-press-and-drag, add notes, and revisit them all later. • Fine-tune your pace: separate pauses for sentences, punctuation, long words, and paragraphs keep fast reading feeling natural. MAKE IT YOURS • Reading speed from a comfortable pace up to 1000 WPM. • Choose your accent color, page background (White, Off-White, Bone, Old Scroll, Pinkish), and anchor shape (Line, Dot, Heart, Diamond, Chevron, Bolt). • Adjustable font size for RSVP and Coasting alike. SEE YOURSELF IMPROVE • Track total reading time, words read, average pace, and your longest session. • Daily and weekly activity, a reading-activity heatmap, and a pace-over-time chart. • Build a daily reading streak and beat your best. FREE & PRO Celeris is free to start: keep up to 3 books, read up to 400 WPM, and track your time and streaks. Upgrade to Pro for unlimited books, speeds up to 1000 WPM, every color, background, and anchor shape, and the full Statistics dashboard. Celeris Pro is available as a monthly or annual subscription. Payment is charged to your Apple ID at confirmation. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period; manage or cancel anytime in your Apple ID settings. Privacy Policy: https://readceleris.app/privacy Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

About

Codex AI

This AI-powered assistant helps you organize tasks, plan projects, and draft content. Simply describe your needs in plain language to generate structured plans, notes, and summaries, streamlining your workflow from idea to action.

Highlights
  • AI assistant for everyday tasks
  • Structured results from simple descriptions
  • Create plans, notes, and summaries
  • Organize work into projects
  • Save and return to sessions
  • Draft content and manage workflows
Features
Read full description

Remote Codex is your personal AI agent for everyday tasks, planning, writing, and project organization. Describe what you need in simple words, and the app helps you turn ideas into clear actions, structured plans, notes, and saved sessions. Use Klyro Forge to organize work, create drafts, plan projects, summarize information, and keep your conversations in one place. With Klyro Forge, you can: • Chat with an AI assistant for everyday tasks • Describe what you need and get structured results • Create plans, notes, summaries, and task lists • Use quick actions for common workflows • Organize work into projects • Save sessions and return to them later • Draft content, prepare ideas, and manage personal workflows Whether you are planning a trip, organizing work tasks, preparing a brief, writing content, or structuring a new project, Klyro Forge helps you move from idea to action faster. Subscription Information Payment: Subscription payments will be charged to your iTunes account upon confirmation of purchase and at the beginning of each renewal period. The subscription automatically renews unless canceled. Cancellation: You can cancel your subscription in your iTunes settings at least 24 hours before the end of the next subscription cycle. Cancellation will take effect on the day after the last day of the current subscription period, and you will be downgraded to the free version of the service. Privacy Policy: https://docs.google.com/document/d/1QXAJqPc0PVbsuVqhS7z-b29eVGOOkvZGtjt8GiRGjDw/edit?usp=sharing Terms and Conditions: https://docs.google.com/document/d/1P6TmjCyH6O897A1_gUd7aKfI8Fd-uchReJmNYn2ogM0/edit?usp=sharing

Screenshots

Celeris4 screens
Codex AI4 screens

Verdict

The call

The clearest difference is review sentiment: Celeris at 100% against Codex AI's 0%. Celeris also leads on rating (5.0 vs 1.0) and in-app purchases (none vs 7). On price, ratings volume, update cadence and ads 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. Codex AI sells 7 in-app purchases, starting at $6.99 per 7 days. Celeris asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

Celeris holds the better App Store score, 5.0 against 1.0. Both are backed by a comparable volume of ratings — 2 and 1 respectively. Written reviews point the same way: 100% of Celeris's written reviews are positive against 0% of Codex AI's.

UpkeepUpdate frequency

Celeris ships an update every 9 days, Codex AI weekly. The most recent releases landed on September 24, 2026 and October 4, 2026 respectively.

Scorecard4 real differences · 6 level
Celeris versus Codex AI: the parameters behind the verdict, then further details
ParameterCelerisCodex AI
PriceFreeFree
Rating5.0 (2 ratings) — better1.0 (1 ratings)
Positive reviews100.0% of reviews — better0.0% of reviews
Number of ratings2 — better1
Update frequencyEvery 9 daysWeekly — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFreemiumFreemium
DevicesiPhone, iPad — betteriPhone
Requires iOS16.4 — better18
Further details — not scored
Size50 MB49 MB
Age rating4+17+
DeveloperHEXAGON WORKS LLCAriadni Deligianni

Customer experience

Celeris

All ratings2 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews1 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

Codex AI

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

None

Celeris

No in-app purchases

7 purchases

Codex AI

Subscriptions2
  • Forge Pro$6.997 Days
  • Forge Pro$49.991 Year
One-time5
  • Tokens$9.99
  • Tokens$19.99
  • Tokens$34.99
Show 2 more
  • Tokens$59.99
  • Tokens$99.99

Questions

Is Celeris free?
Celeris is free to download, with no in-app purchases.
Is Codex AI free?
Codex AI is free to download, with in-app purchases available.
Which has better reviews, Celeris or Codex AI?
Celeris is rated higher. Celeris averages 5.0 out of 5 from 2 ratings, while Codex AI averages 1.0 from 1 ratings.
Do Celeris or Codex AI have ads?
Neither Celeris nor Codex AI shows ads.
Which is updated more often, Celeris or Codex AI?
Celeris ships an update every 9 days, and Codex AI weekly. Most recently, Celeris was updated on September 24, 2026 and Codex AI on October 4, 2026.

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