# marrow - scroll to learn — Learn one idea at a time > Learn one idea at a time (iPhone/iPad app by Pratyush Saxena.) - Source: https://appshunter.io/ios/app/marrow-scroll-to-learn/id6791669414 (this page in markdown: same URL + `.md`) - Developer: [Pratyush Saxena](https://appshunter.io/developer/1896770612) - Category: Education, Reference - Price: Free - Age rating: 4+ - Requires: iOS 16.4 · 40 MB - Languages: American English - Released: 2026-07-27 - Data updated: 2026-08-28 - User reviews in markdown: https://appshunter.io/ios/app/marrow-scroll-to-learn/id6791669414/reviews.md ## What is marrow? marrow is a feed of ideas worth keeping. Instead of an endless scroll of noise, you move through short, self-contained explanations (one concept per screen) across computer science, finance, math, and science. Each card explains a single idea in a few sentences: why appending to a dynamic array is O(1) on average, what the Rule of 72 estimates, and dozens more. Some cards ask you a question first. Reveal the answer, then tell marrow how well you knew it. The ones you find hard come back sooner; the ones you already know drift further out. That is spaced repetition, built into the scroll, so the ideas you want to keep actually stick. - One idea per screen, made for short sessions - Four domains: computer science, finance, math, and science - Self-grading with spaced repetition, so reviews return at the right time - Fully offline: no account, no ads, no tracking. Your progress stays on your device. Scroll to learn. ## Version history (last 4 releases) ### 1.3.0 — 2026-08-18 A home screen widget. One concept a day, in three sizes, following the subjects and levels you chose in the app. Tap it to open that card. ### 1.2 — 2026-08-15 40 new concepts, bringing the library to 270 across computer science, finance, math and science. Among them: Amdahl's law, the impossible trinity, Bayesian updating, why antibiotics do not touch a virus, and what GDP was never built to measure. Every one of the existing 230 cards has been rewritten. Shorter where the idea was short, clearer throughout, and with a lot more of the sources pointing at the primary reference rather than a general one. Every source link in the app now resolves. Fixed the app icon in the Clear and Tinted home screen appearances, where the ring around the card was disappearing on light backgrounds. ### 1.1 — 2026-08-14 A new look throughout, and a new app icon. - Long cards no longer get clipped once the answer is showing - Switching tabs no longer slides in from the side - Grading a card carries you on to the next one - Progress shows your last four weeks as a calendar heatmap instead of thin bars - Haptics when you select, commit, and finish a quiz - Consistent buttons, icons, and labels on every screen ### 1.0 — 2026-07-28 No release notes. ## More apps by Pratyush Saxena - [drizzle - find your people](https://appshunter.io/ios/app/drizzle-find-your-people/id6771082416) All apps by Pratyush Saxena: https://appshunter.io/developer/1896770612 --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-28.*