Beatcode vs LockFeed

Many coding interview problems are a handful of patterns in disguise. Beatcode teaches those patterns the way they actually click: by letting you be the algorithm. LEARN BY DOING Every lesson puts a real algorithm in your hands. Slide the window, move the pointers, push onto the stack, fill the BFS queue. A real implementation checks every move, and when you make a wrong one, Beatcode plays it out so you can see exactly why it fails. FEEL WHY IT’S FAST Try the obvious way first and watch the work pile up. Then do it with the pattern and see the gap at real interview scale: 10,000 steps instead of 50 million. PROVE IT, THEN CODE IT Short “why is this safe?” questions lock in the invariant behind each pattern. Then tap through the Python line by line as the board follows along, and fill in the template yourself. SPOT THE PATTERN Interviews test recognition. Every lesson ends by spotting the pattern in a fresh problem, and Pattern Radar is a fast-paced round that trains you to name the right tool. Misses come back until they stick. LOCK DISTRACTING APPS App lock keeps the apps you choose locked each day until you practice. Pattern Radar, a Practice board or your next lesson unlocks them until midnight. SEVEN PATTERNS, FREE • Two Pointers • Hash Map • Sliding Window • Binary Search • Stack (including the monotonic stack) • Intervals • Breadth-First Search FOURTEEN TRICKS (BEATCODE PRO) Short lessons on the clever one-off ideas interviewers love, open after your first two patterns: • XOR Cancellation • Fast and Slow Pointers • Boyer–Moore Majority Vote • Prefix Sums with a Hash Map • Index Marking • Kadane’s Algorithm • Dutch National Flag • Rotate by Reversing • Union-Find • Trie (Prefix Tree) • Dijkstra’s Algorithm • Greedy (Farthest Reach) • Bit Masks (Sets as Numbers) • Two Heaps (Running Median) KEEP IT GOING • Collectible pattern cards with cues, invariants and templates • Daily streak, trophies and Game Center leaderboards • Rewards: spend your XP on streak protection and more • Endless practice boards with fresh inputs and a three-star score • Solve the real one: after each lesson, try a real interview problem with a Lock Screen timer and hints you unlock one at a time EVERYWHERE YOU ARE • Home Screen widgets: answer a Spot It card right from the widget, keep an eye on your streak, or jump into your next lesson • Lock Screen and StandBy widgets, plus a Control Center button for a quick Radar round • Answer the daily reminder’s card straight from the notification • Apple Watch: your pattern cards, complications for your streak and a Spot It card, and quick Radar rounds with haptics • Siri: “Quiz me in Beatcode” BEATCODE PRO The seven core lessons and their practice boards, challenges, Radar questions and real interview problems are free. Beatcode Pro unlocks the remaining lessons and their content on iPhone, Apple Watch and widgets. Pattern cards, trophies, your streak, reminders and Game Center are also free. • Beatcode Pro Monthly: $7.99 a month • Beatcode Pro Yearly: $39.99 a year, with a 7-day free trial for new subscribers Prices are in US dollars and may vary by country. Payment is charged to your Apple Account when you confirm the purchase, or when the free trial ends. Subscriptions renew automatically at the same price unless auto-renew is turned off at least 24 hours before the end of the current period; your account is charged for renewal within 24 hours before the period ends. Manage or cancel anytime in your Apple Account’s subscription settings. Any unused part of a free trial ends when you subscribe. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://beatcode.app/privacy/ PRIVATE BY DESIGN You can learn without signing in. Optional Game Center features use your Apple Account. Your learning progress stays on your devices and in your iCloud, and purchases go through Apple. Beatcode has no ads and does not track you across apps or websites.

Earn your screen time with a little learning. LockFeed puts a short challenge before the apps you choose. Enable one or more quizzes, choose how many questions to complete, and use Apple Screen Time to add a pause before you scroll. HOW IT WORKS • Choose the apps you want to lock. • Enable quizzes and choose how many correct answers you need to unlock. • Set a default unlock time, with optional custom times for individual apps. • Complete your challenge to unlock the app you want to use. • When your unlock time ends, the app locks again. MAKE EACH UNLOCK YOUR OWN Start with one question per unlock, or choose up to 10. Each completed quiz round counts as one question. Your progress is saved if you leave before finishing. Use Manage Apps to Lock to add or remove apps and give each app its own unlock time, or let it follow your default. Changing a time does not cut short an unlock you have already earned. FIVE FREE APP UNLOCKS Try five successful quiz-based app unlocks. After those five unlocks, Lifetime Access is required for further unlocks. Each earned unlock lasts for the full duration you chose. LIFETIME ACCESS A one-time in-app purchase enables unlimited quiz-based app unlocks and standalone quiz practice. Standalone practice requires Lifetime Access. There is no subscription, and the price for your region is shown before purchase. Restore Purchases is available for previous buyers. FIND SOMETHING YOU WANT TO LEARN Practice vocabulary, identify famous artworks and country flags, solve chess puzzles, or find notes on a guitar fretboard. Read short Python functions and identify their time complexity, or explore practice questions in math, science, exam preparation, driving theory, and citizenship. Learn about AI with LLM Fundamentals and Practical Deep Learning: 304 questions with explanations and links to supporting lessons. Questions and explanations work offline; opening source lessons requires an internet connection. Your enabled quizzes form a shared pool across your protected apps. The quizzes take turns in a shuffled order, with each getting a turn before repeating. When you require multiple answers, each question advances to the next quiz in the rotation. Manage your enabled quizzes or adjust your unlock settings anytime. Quiz content is bundled for offline use, and no account is required. CHOOSE YOUR STYLE Switch between Classic and a neutral black-and-white Dark appearance in Settings. Your lock screens follow your chosen style, while quiz artwork keeps its original colors. HAVE AN IDEA OR NEED HELP? Use the Feedback tab to write a message and send it to joma@lockfeed.app from your email account. Unsent drafts are saved on your device. LockFeed uses Apple Screen Time permission to manage access to the apps you select. Short practice quizzes are learning aids, not complete exam preparation courses or official exam simulations.