Cleverlope — snail-mail STEM letters for kids ages 4–10
Snail mail · STEM · Ages 4–10Every month, Leo & Liza send a real paper letter packed with curiosity, dares, and one kitchen experiment that needs no instructions — just a kid.
Five small things, one big moment
Every envelope is hand-stuffed with these five pieces, designed to be opened on the kitchen floor.
Leo's Letter
~80 words of pure excitement. Stories, dares, the occasional disaster. Written like a real kid, not a curriculum.
Mission Card
A hands-on experiment using things already in your kitchen. Leo's idea, he already tried it (and made a mess).
Collectible Fact Card
#1 of 24. Front and back, fully illustrated. Kids collect the whole set over 12 months.
Write-Back Card
Addressed to Leo, with a riddle, drawing prompt, and a rating. Your kid writes back. We read every one.
Sticker Sheet
Themed to the topic. Ends up on notebooks, water bottles, and the dog.
Science in an envelope.
Joy in the mailbox.
Sign up
Pick your child's age group and language. Tell us their name. Leo will use it.
Letters arrive
Two envelopes land in your mailbox every month, on the 1st and 15th.
Explore & play
Read Leo's letter, try the experiment, collect the fact card, fill in the stickers.
Write back
Your child responds to Leo on the pre-stamped postcard. Drop it in the mailbox!
Two tiers, one curious kid
Same Leo, same magic in the mailbox, written for exactly where your kid is right now.
"Big letters. Big pictures. Big feelings."
Chunky words, picture-led missions, and experiments a grown-up can help with (or not).
- Short, chunky sentences
- Picture-heavy layouts
- Kitchen experiments with a grown-up
- Sticker rewards on every card
"Longer letters. Messier missions. Bigger questions."
Full paragraphs, trickier experiments, and write-back prompts that actually make them think.
- Full paragraphs & wordplay
- Two-step experiments
- Deeper facts on collectible cards
- Riddles and code-cracking
Not sure which tier? Pick the younger one, you can swap anytime.
A pen pal, not a teacher
Leo is a curious kid who finds out something cool and can't wait to tell your kid about it. He tries stuff and it goes wrong. He dares the reader. He writes in ALL CAPS when he's excited.
You'll never see Leo. Neither will your kid. He lives in their imagination, exactly where pen pals belong.
Hi! I just found out volcanoes have something WILD going on inside them and now I can't stop thinking about it. Mom said I can't make one in the kitchen but YOU should. I dare you. Tell me what happens. Postcard's in the envelope.
Leo
24 topics.
4 pillars.
1 mailbox
A curated curriculum hidden inside friendship. Every letter arrives on its own — but together they map a full year of wonder.
Science & Nature
6 letters
- Volcanoes
- The Moon
- Bones
- Storms
- Bees
- The Deep Sea
Math & Logic
6 letters
- Patterns
- Codes & Ciphers
- Shapes in Nature
- Big Numbers
- Probability
- Maps
Reading & Literacy
6 letters
- Tall Tales
- Word Origins
- Mysteries
- Poetry
- Letters & Mail
- Headlines
Geography & World
6 letters
- Iceland
- Mongolia
- The Amazon
- Antarctica
- Istanbul
- Madagascar
Available in your language
Same science, same Leo, same magic, in the language your family speaks at home. We're launching in English and Russian first, with more coming based on demand.
Choose your plan:
Subscriptions open August 1st, 2026. Join the waitlist now. The first 50 sign-ups lock in the founding rate for as long as their subscription stays active.
Lock in this rate at launch, for as long as your subscription stays active. Only for the first 50 waitlist sign-ups.
Claim founding rate →Questions, answered
What age is this for?+
Cleverlope is designed for kids 4–10, with two tiers: Explorers (4–7) and Adventurers (8–10). You pick the tier when you subscribe.
What's inside each envelope?+
Seven things: Leo's letter, a mission card with an experiment, a collectible fact card, a write-back card addressed to Leo with a riddle and drawing prompt, a sneak peek slip, a sticker sheet, and a note for parents.
How is this different from a subscription box?+
It's not a box, it's mail. Real letters in a real envelope, addressed to your kid by name. Lighter, cheaper to ship, and a thousand times more magical when it lands in the mailbox.
Can I get this in my language?+
English and Russian are available at launch. Spanish, Mandarin, Ukrainian, and Korean are on the waitlist. Sign up below and we'll launch your language as soon as we hit critical mass.
Who is Leo?+
Leo is a curious kid who writes to your kid twice a month. He shares discoveries, dares them to try things, and writes the way real kids write, in ALL CAPS when he's excited. He's a pen pal, not a teacher.
Can my child write back?+
Yes, every envelope includes a write-back card addressed to Leo, with a riddle, drawing prompt, and rating. We read every one.
What if we miss a letter?+
Letters arrive on the 1st and 15th. Missed one? Email us and we'll resend it.
Do you ship internationally?+
We ship to the US, Canada, UK, EU, and Australia at launch. More countries coming. Email hello@cleverlope.com if yours isn't listed.