Not sure which words to learn next? zeroStudy now highlights words close to your level while you watch, so you can mark them with a tap.
Turn the YouTube videos you already enjoy into a language-learning routine. zeroStudy brings interactive subtitles, vocabulary capture, and spaced repetition together, so watching, understanding, and remembering flow in one place.
LEARN WITH YOUTUBE
• Paste a YouTube link and watch without leaving zeroStudy.
• Follow interactive subtitles as the video plays.
• Select a word or phrase to understand and save it in context.
• Continue recently watched videos and track your daily immersion progress.
REMEMBER WITH REINFORCE
• Review vocabulary with spaced repetition at the right time.
• Use active recall to build durable memory.
• Hear pronunciation and revisit the original sentence.
• Add your own words and phrases manually, with optional AI Auto Fill.
• Track your streak, retention, and learning progress.
KEEP YOUR LEARNING CONNECTED
Your vocabulary and progress stay synced across zeroStudy. The optional Chrome extension gives you another way to collect vocabulary while watching on desktop, but it is not required to use the iPhone app.
Watch what you enjoy. Save what matters. Reinforce what you want to remember.
Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
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New Word Hints help you decide what to learn next. While you watch, words you have not marked yet that are close in level to your Learning words are highlighted in yellow with an underline, both in the subtitle bar and in the transcript. Marking a word removes the highlight right away.
Tap a highlighted word to see why it was suggested: how many times it appears in this video, and whether it is close to your current level or simply a common word in shows and films that you have not marked yet.
Hints are available for English, Spanish, Chinese and Korean subtitles, and only when the subtitle language matches the language you are learning. They are on by default. In Settings, open New Word Hints to turn them off, or to read about the word frequency data and its license.
Version 1.16.0
The developer, JIA JIUN Ku, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
Contact Info
User Content
Browsing History
Usage Data
Privacy practices may vary, for example, based on the features you use or your age. Learn More
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
Seller
JIA JIUN Ku
Size
45.5 MB
Category
Education
Compatibility
Requires iOS 15.1 or later.
iPhone Requires iOS 15.1 or later.
iPad Requires iPadOS 15.1 or later.
iPod touch Requires iOS 15.1 or later.
Mac Requires macOS 12.0 or later and a Mac with Apple M1 chip or later.