Comparison

Principal Task vs 23Brain

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

Head to head
About

Principal Task

This app helps you manage tasks by tracking your completion rate against new tasks created. It offers a unique 'Task Velocity' score to show if you're keeping up with your workload. Organize with folders, contexts, and priorities, with advanced features available through a premium subscription.

Highlights
  • Task Velocity score
  • GTD-native structure
  • Due dates and repeating tasks
  • Markdown support
  • Kanban boards
  • Private templates
Features
Read full description

Track your Task Velocity — the ratio of tasks you complete against the ones you create, updated every day. See at a glance whether you're ahead or falling behind, not just what's on your list. Principal Task is a GTD-native task manager built for people who've outgrown to-do apps. Folders, contexts, priorities, statuses, and unlimited nested subtasks — organized the way real work actually happens. TASK VELOCITY Your 30-day completed-vs-created ratio, shown as a simple multiplier. Free members see their current score. Premium unlocks the full history, filterable by folder, context, priority, and status. SYSTEM HEALTH A live verdict — Healthy, Strained, or Overloaded — so you know where things stand today, separate from where they're heading. BUILT FOR GTD Folders and sub-folders, contexts, priorities, statuses, and stars. Subtasks nest as deep as you need, with independent completion — no forced parent-child status. KANBAN, HEATMAP, TEMPLATES See your work as a board. Watch your activity over time. Turn repeatable processes into templates you can apply in one tap. BUILT FOR AI ASSISTANTS Principal Task connects to AI assistants over MCP — read and write your tasks, subtasks, and folders directly from the assistant you already use. SHARE WITHOUT FRICTION Share a task list with a four-word link. No account required to view. You control how long it stays open. Free, no credit card. Premium is about $3/month or $24/year, and it doesn't limit how much you can do — it unlocks Task Velocity history, Kanban, the Activity Heatmap, and private templates. Principal Task. Software that gets out of the way. Terms of Use: https://principaltask.com/terms

About

23Brain

Read full description

Your second and third brain for smarter learning 23Brain helps you collect, summarize, and retain knowledge from everything you read, watch, or listen to — powered by AI. Build a personal learning system that grows with you. How it works • Summarize any content automatically Save links, videos, or PDFs — 23Brain generates concise, AI-powered summaries. • Learn on the go Listen to audio summaries anywhere and make use of your time more efficiently. • Organize with collaborative collections Group related topics, share insights, or explore curated watchlists. • Retain knowledge with AI-generated quizzes Reinforce what you’ve learned through personalized quizzes that adapt to your interests. • Chat with your second brain Ask questions, connect ideas, and reflect on what you’ve learned through intelligent conversations. • Track your progress Stay motivated with streaks, insights, and detailed learning statistics. Why 23Brain Unlike traditional note-taking tools, 23Brain helps you remember more and understand faster — not just store information. It’s your personal AI companion for continuous learning and long-term growth. Key features • AI summaries for articles, videos, and podcasts • Audio playback for summaries • Personalized quizzes and progress insights • Collaborative collections and watchlists • Multi-language support for 12 languages including English, German, and Hindi • Light and Dark Mode Start building your second brain today. Turn what you learn into knowledge that lasts.

Screenshots

Principal Task4 screens
23Brain4 screens

Verdict

The call

The clearest difference is update cadence: 23Brain at every 8 days against Principal Task's every 3 months. 23Brain also leads on iOS requirement (13.0 vs 15.0). 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. Principal Task sells 2 in-app purchases, starting at $3.99 per month and 23Brain sells 4 in-app purchases, starting at $12.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Principal Task ships an update every 3 months, 23Brain every 8 days. The most recent releases landed on October 1, 2026 and October 9, 2026 respectively.

Scorecard2 real differences · 7 level
Principal Task versus 23Brain: the parameters behind the verdict, then further details
ParameterPrincipal Task23Brain
PriceFreeFree
Rating5.0 (1 ratings) — better—
Number of ratings1 — better—
Update frequencyEvery 3 monthsEvery 8 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPod — betteriPhone, iPod
Requires iOS15.013.0 — better
Further details — not scored
Size32 MB76 MB
Age rating4+4+
DeveloperZechariah SchwenkFelix Seip

In-app purchases

2 purchases

Principal Task

Subscriptions2
  • Monthly Subscription$3.991 Month
  • Annual Subscription$29.991 Year
4 purchases

23Brain

Subscriptions4
  • Pro (Monthly)3 Days trial$12.991 Month
  • Ultra (Monthly)3 Days trial$24.991 Month
  • Pro (Yearly)3 Days trial$99.991 Year
Show 1 more
  • Ultra (Yearly)3 Days trial$249.991 Year

Questions

Is Principal Task free?
Principal Task is free to download, with in-app purchases available.
Is 23Brain free?
23Brain is free to download, with in-app purchases available.
Do Principal Task or 23Brain have ads?
Neither Principal Task nor 23Brain shows ads.
Which is updated more often, Principal Task or 23Brain?
Principal Task ships an update every 3 months, and 23Brain every 8 days. Most recently, Principal Task was updated on October 1, 2026 and 23Brain on October 9, 2026.

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