Focustack

EARLY ACCESS

We're building a better
way to learn from YouTube.

Add a link to a YouTube video or playlist and learn at your own pace, away from the recommendation feed. Take notes, create practice tasks, review with flashcards, and ask AI questions about your lesson — all in one workspace.

Join the Beta Waitlist

Free during beta · By invitation · Desktop or laptop

Watch
Save
Ask
Return

SQL for data analysis

2h 30m · 2/10 done

Progress20%

1Meet your data
2Select the columns
you need
3Filter rows with WHERE
4Sort your results
5Summarize with aggregates
6Group and compare
7Join two tables
8Handle missing values
9Work with dates
10Build a sales report

Filter rows with WHERE

SELECT order_id, total
FROM orders
WHERE total > 100;

Keep only the orders that match your condition.

Filter a dataset to answer a specific business question.

18:40·Oct 28, 2026

NotesBookmarksTasksFlashcards

Add

02:10

Start with a clear question

Which orders are worth more than $100?

03:15

Include the boundary

Use >= 100 to include orders of exactly $100.

04:32

WHERE filters rows

Only rows that match the condition stay in the result.

SQL for data analysisLesson 3 of 10

Filter rows with WHERE

SELECT *
FROM orders
WHERE total > 100;

OrderTotal

#1041$40

#1042$100

#1043$160

04:32

WHERE filters rows

Only rows that match the condition stay in the result.

Flia Current lesson

Your AI study assistant

How do I find orders of $100 or more, but only the ones that have already been paid? How do I combine those conditions?

Use >= for the amount and AND to add the payment condition:

SELECT *
FROM orders
WHERE total >= 100
  AND status = 'paid';

Both conditions must be true. A paid $100 order will appear; an unpaid $160 order will not.

This assumes payment status is stored in a column named status.

Ask about this lesson…

Watch the explanation.
Follow along with the video at your own pace.
Save an insight.
Take timestamped notes you can easily find later.
Ask a question.
Get instant, contextual help from an AI assistant, right in your workspace.
Resume with context.
Pick up where you left off with your progress saved.

Keep track of your learning.

Focustack is built for people who use YouTube to develop skills and explore new subjects. Bring the material that interests you and organise your learning around a topic, a skill, or a course you want to complete.

Return to the explanation you need.

Timestamped notes and bookmarks help you find a specific moment in a lesson and revisit it in context.

Keep working on the topic.

Save tasks you want to complete and flashcards to review. Mark lessons as complete to see your progress.

How it works

Turn a link into something you keep.

Add a YouTube link
Start with a video or playlist.
YouTube link
Spanish basics9:40
Spanish for beginners
Ordering coffee
Explore the lesson
Ask questions and capture what matters.
Notes
02:14
Ordering politely
Quisiera un café, por favor.
I’d like a coffee, please.
“Quisiera” is a polite way to say “I’d like.”
Put it into practice
Review flashcards. Try a task. Keep going.
Flashcard1 / 8
How do you say
“I’d like a coffee”?Quisiera un café.Show answerHide answer
Practice ordering a drink in Spanish.

Request early access

Understand it.
Put it into practice.

Get help with your lessons, try what you’ve learned, and work through questions along the way.

Meet FliaYour AI assistant

01 / CONTEXT → CLARITY

Stay with the idea.

Ask about a video moment, lesson, or saved note. Flia uses that context to help you understand.

02 / IDEAS → PRACTICE

Put an idea into practice.

Try a short exercise from your lesson. Get hints as you go and discuss your answer with Flia.

03 / LIBRARY → NEXT STEPS

Find your next step.

Get help choosing what to study or revisit next from the materials in your library.

Your YouTube courses.
A dedicated learning workspace.

Watch lessons, capture timestamped notes, ask AI questions, and track your progress in one place.

Learning workflows comparison
When learning directly on YouTube	With Focustack
Save videos and links to specific moments	Keep timestamped notes and bookmarks beside the lesson
Find videos through search and watch history	Search your saved notes, bookmarks, tasks, and flashcards
Use course quizzes, where available	Create your own lesson tasks and flashcards
Manage practice tasks in a separate tool	See open learning tasks across your playlists
Rewatch lessons or take available course quizzes	Review your own flashcards across lessons in one session
Ask about the video, where AI is available	Ask Flia about a lesson moment, saved note, or bookmark
Follow your viewing progress in Courses	Keep lessons, notes, practice, and progress together
Watch in the standard YouTube interface	Expand the lesson, with study tools one click away

Your questions, answered.

A few things to know
about learning with Focustack.

How does early access work?

Request an invitation with your email and a short description of what you’d like to learn. The beta is for adults 18+, with initial invitations focused on the US. We invite people gradually by email and can’t promise an invitation date. Newsletter subscriptions don’t request beta access.

Is Focustack free, and are there any limits?

Focustack is free throughout the beta. Limits apply to playlists and AI usage. Pricing after the beta hasn’t been announced.

Which YouTube videos and playlists can I use?

Start with a YouTube video or playlist link. Private videos and playlists aren’t supported, and videos need to allow embedded playback.

Can I use Focustack on my phone?

Focustack is designed for desktop and laptop browsers. Mobile support isn’t available. Before you start, we recommend putting your phone aside, turning off notifications, and clearing away anything that distracts you. Stay focused!

What can Flia AI use as context?

Flia AI works with the context you select, such as a video moment, a full lesson, or saved notes, bookmarks, tasks and flashcards. For playlists, it uses prepared lesson summaries, which may not cover every lesson yet.

Do I create my own study materials?

You create and save your notes, tasks and flashcards. Flia AI helps explain ideas, suggests exercises and discusses your answers. It doesn’t automatically create or save items in your workspace.

Does Focustack replace YouTube?

No. The videos still come from YouTube. Focustack adds a learning workspace around them, with your notes, bookmarks, practice materials and Flia AI alongside the lesson.

We're building a better way to learn from YouTube.

Filter rows with WHERE

WHERE filters rows

Watch the explanation.

Save an insight.

Ask a question.

Resume with context.

Keep track of your learning.

Return to the explanation you need.

Keep working on the topic.

Ordering politely

Stay with the idea.

Put an idea into practice.

Find your next step.

See what’s next.

We're building a better
way to learn from YouTube.