Calcumber's answer

• Easy to use calculator notebook
• From simple arithmetic to advanced engineering with units
• Installation optional
• Send calculation link with full privacy
• Embed calculation templates, exercices and soultions in documents or interactively in web pages

Learzo's answer:

• You own what you buy. Every course is a one-time purchase with lifetime access. No subscription to cancel, no expiring "access window" — your courses are yours forever, like a book.
• Curation, not catalog. Instead of 250,000 random courses (Udemy) or a closed subscription bundle (MasterClass), Learzo hand-picks a small set of legit courses from the world's best teachers. Every listing is vetted before it goes live.
• Real instructors with real authority. Tony Robbins, Russell Brunson, Vanessa Van Edwards, Charlie Houpert, CopyHackers, Patrick Nill — each course on Learzo is built by someone who has actually done the thing they're teaching.

We're betting that course buyers want a "shop" experience like Apple's Today tab — not a Netflix experience or an open marketplace race-to-the-bottom.

Calcumber's answer

• Sharing calculations and embedding them in documents or web pages is perfect for education.
• Natural unit support, just include them in your expression and Calcumber handles it.
• Free and easy access to thermodynamic fluid-properties.

Learzo's answer:

The case against each major alternative:

• vs MasterClass ($180/yr subscription): Lose access the moment you cancel. With Learzo, the course stays yours forever — buy once, own it.
• vs Coursera ($399/yr Plus): Same problem — rented education. Plus their catalog is mostly recycled university lecture material, not practical business training.
• vs Udemy (open marketplace): 250,000 courses with no quality bar. Inflated ratings, the "Become a millionaire in 30 days" problem. Learzo's small curated catalog removes the decision fatigue.
• vs Skillshare: Same subscription lock-in, mostly creative courses, no real business depth.
• vs buying direct from creators: Direct stores work, but you have no discovery path until you already follow the instructor. Learzo gives you the "Pitchfork for business education" — independent curation you can trust.

Net: own your courses + trust the catalog. That's the whole pitch.

Calcumber's answer

• The notebook-style calculator is great for everybody who wants more than just a single line calculator.
• The sharing and embedding features make it Calcumber very well suited for teachers and students. The power of consistently using units is shown immediatly.
• Engineers will like the unit support, sharing calculations with collegues and if needed the built-in fluid properties calculation.

Learzo's answer:

Three overlapping personas:

• The frustrated subscription escapee. Has tried MasterClass, Coursera, Skillshare — got tired of paying monthly and losing access the moment they cancel. Wants ownership, not rental.
• The serious self-improver. Buys $300-$1000 courses regularly, has spent hours researching whether "Course X" is worth it. Wants a trusted curator who's already done the vetting.
• The indie operator. Founders, freelancers, agency owners, traders, course creators, and copywriters who need practical skill upgrades fast — not academic theory.

What they share: they value time (so they trust curation), ownership (so they reject subscriptions), and practical depth (so they prefer one $497 course from a real practitioner over 50 cheap courses from anonymous instructors).

Calcumber's answer

When starting for a Master of Advances Study in Energy Systems, I was looking for a suitable state-of-the-art calculator. Then I built my own Calculator Calcumber and now the Eastern Switzerland University of Applied Sciences is using Calcumber for teaching students in thermodynamics.

Learzo's answer:

Learzo started as a personal frustration. After buying online business courses across MasterClass, Coursera, Udemy, and 20+ creator-direct platforms over 8 years, the pattern became impossible to ignore:

• Subscription platforms held my education hostage. The moment I cancelled, courses I'd "completed" vanished from my dashboard.
• Open marketplaces (Udemy) were a flooded mess. 250,000 courses, fake reviews, no way to know what was actually worth the time.
• Direct creator stores were honest but scattered. No central discovery, no quality signal, no shared trust layer.

There was no "Apple Store" for online business education — a curated, owned, trusted catalog. So I built it. Started with 9 hand-picked courses from instructors I'd personally bought from and could vouch for (Tony Robbins, Russell Brunson, Vanessa Van Edwards, CopyHackers, Charlie Houpert). Adding more on a strict curation review every month — quality bar first, catalog size second.

Bootstrapped, solo-founded, currently in soft-launch phase. Public launch in mid-2026.

Calcumber's answer

HTML, CSS, TypeScript, PWA, CoolProp

Learzo's answer:

Modern Next.js stack, optimized for SEO and conversion:

• Frontend: Next.js 16 (App Router), React 19, TypeScript 5, Tailwind CSS v4, Radix UI
• Backend: Next.js API routes + Drizzle ORM
• Database: PostgreSQL (Supabase)
• Payments: Stripe, PayPal, Coinbase Commerce (crypto)
• Email: Nodemailer + Mailgun + MJML templates with custom automation engine
• Search: Meilisearch
• Hosting: Docker on dedicated VPS, Cloudflare CDN edge
• Analytics: GA4, PostHog, Sentry
• Page Builder: ChaiBuilder for editorial pages

Deployed via a hardened deploy pipeline with automatic Cloudflare cache purging and ISR revalidation. Built solo by the founder — no engineering team, just clean modern tooling.

Calcumber's answer

Eastern Switzerland University of Applied Sciences

Learzo's answer:

Learzo is in soft-launch phase (public launch mid-2026), so the customer base is still early-stage and not yet public. Instead, here's the more meaningful answer — the biggest instructors whose courses are sold through Learzo:

• Tony Robbins (Business Mastery Program)
• Russell Brunson (Course Secrets)
• Vanessa Van Edwards (People School)
• Charlie Houpert (Charisma University)
• CopyHackers / Joanna Wiebe (Copy School)
• Patrick Nill (TTT Mentorship — trading)
• Sunny Lenarduzzi (YouTube for Bosses 3.0)
• Richmond Dinh (Tiny Challenge Course)
• William Souza (AIA Premium Method)

Customer testimonials and case studies will be added as the post-launch base grows. For early access to current customer breakdowns, reach out via the contact page.