Welcome to HackerNoon’s Projects of the Week, where we spotlight standout projects from the Proof of Usefulness Hackathon, HackerNoon’s competition designed to measure what actually matters: real utility over hype.Each week, we’ll highlight projects that demonstrate clear usefulness, technical execution, and real-world impact - backed by data, not buzzwords.This week, we’re excited to share three projects that have proven their utility by solving concrete problems for real users: RecallNote, ACHLS Eternal, and Rivver Accountant.Want to see your own project spotlighted here?Join the Proof of Usefulness Hackathon to get on our radar.Meet the Projects of The WeekRecallNotehttps://hackernoon.com/recallnote-earns-a-37-proof-of-usefulness-score-by-building-ai-summarized-notes-and-spaced-repetition-notifications?embedable=trueRecallNote is an EdTech solution designed to help students and self-learners fight the forgetting curve through personalized, AI-generated study concepts and spaced repetition.RecallNote solves the problem of forgetting 70% of lecture material within 24 hours by turning notes into AI-summarized, personalized concepts using Google’s LearnLM, vibrant flashcards, offline storage, and spaced repetition notifications for 50% better retention. It focuses on students and self-learners who need to retain what they read.Proof of Usefulness score: +37 / 1000See RecallNote’s full Proof of Usefulness reportRead their story on HackerNoonACHLS Eternalhttps://hackernoon.com/achls-eternal-earns-a-12-proof-of-usefulness-score-by-building-an-automated-materials-science-and-medical-lab-complex?embedable=trueACHLS Eternal is a proof-of-concept that aims to revolutionize the scientific method by combining an automated materials science and medical lab complex with a cognitive synthetic architecture trained on grounded data.The concept combines an automated materials science, a medical lab complex with 135 different state vector labs, and a cognitive synthetic architecture LLM based off concepts by Tononi of IIT and Global Workspace Theory.Proof of Usefulness score: +12 / 1000See ACHLS Eternal’s full Proof of Usefulness reportRead their story on HackerNoonRivver AccountantRivver Accountant is an AI-powered personal wealth management platform tailored for the Caribbean. By aggregating financial data and providing intelligent insights, the project helps a new generation of earners better manage, save, and grow their wealth.The AI and Automation revolution will definitely bring volatility to jobs, income and investments, so Rivver is building financial tools so users know where they are, where they are going and how to get there.Proof of Usefulness score: +51 / 1000See Rivver’s full Proof of Usefulness reportRead their story on HackerNoonWant to submit your project to the Proof of Usefulness hackathon?What is Proof of Usefulness?It's our answer to a web drowning in vaporware and empty promises. We evaluate projects based on:▪️ Real user adoption▪️ Sustainable revenue▪️ Technical stability▪️ Genuine utilityTest your project’s usefulness and submit your report on Hackernoon before August 10, 2026, to compete for over $150,000 in cash prizes and software credits.Projects score from -100 to +1000. Top scorers compete for $20K in cash and $130K+ in software credits.You’ll be in good company. The hackathon is backed by teams who ship production software for a living - Bright Data, Neo4j, Storyblok, Algolia, and HackerNoon.What happens when you submit:1. Get your free Proof of Usefulness score instantly2. Your submission becomes a HackerNoon article (published within days)3. Compete for monthly prizes4. All participants get rewardsComplete guide on how to submit here.👉 Submit Your Project Now!That’s all for now.Until next time, Hackers!