Your own weather.
The days when the moving sky meets your birth chart. See what’s exact, what’s in reach, and a practice to try.
AN ALMANAC FOR ONE. OR TWO.
Your sky.
The sky between you.
A little more perspective on the days ahead. Tandem brings your personal astrology into one quiet calendar — for you, your partner, and the relationship you share.
£29.99once at launch
No subscription.
Be there at launch No subscription.
Planned for 3 October 2026 · iPhone
Actual app screen · September example
BOUGHT ONCENO APP ACCOUNTYOUR PARTNER NEEDS NOTHING
01 / THREE WAYS TO LOOK UP
One calendar.
Three perspectives.
The sky between you.
Your relationship read as its own chart. A shared perspective, without asking your partner to install anything.
A little more understanding.
See their calendar alongside yours. Space to be curious about each other, without turning a chart into a verdict.
02 / A GLANCE IS ENOUGH
The month ahead.
Right at home.
The calendar widget keeps the next marked days on your iPhone’s home screen. Open Tandem when you want the detail.
Every day page ends with The Work: a small practice — something to talk about, do, ask or reflect on. Something you can bring into an ordinary day.
03 / WRITING WITH SOMETHING TO ANSWER TO
The astrology app
that checks its own AI.
A month letter. A day read in full. An evening debrief. A question about the day you’re living.
Choose your writer. Each letter is checked, claim by claim, against the ephemeris before you see it — and rewritten if it contradicts the engine.
4 writers, your choice300 starter credits includedOptional top-ups, no expiry
“The sky describes weather;
it never causes.”THE TANDEM HOUSE RULE
YOUR INVITATION TO THE FIRST DAY
A little perspective.
In your pocket.
Join the launch list for a closer look at Tandem and an email when it’s ready.
£29.99 once at launch · 300 letter credits included
Planned launch: 3 October 2026. iPhone. Local App Store prices may differ.
A FEW THINGS YOU MIGHT WONDER
Before you join.
Does my partner need the app?
No. You can add your partner’s birth details, with their permission, on your own phone. They need no app, account or invitation. You can also use Tandem just for yourself.
What if I don’t know my birth time?
You can use Tandem without it. Houses and angles are omitted when the time is unknown, and the app makes that limitation clear.
What does “Together” mean?
Tandem computes a composite chart for the relationship, with synastry cross-aspects. It reads the sky between you as a chart in its own right.
What do I pay for?
The launch price is £29.99 once for the almanac, with 300 starter credits for letters. Further letters use optional credit top-ups. You see the credit cost before each request. There is no subscription, and credits never expire. Local App Store prices may differ.
What does the AI check cover?
Every letter’s astrological claims are checked against the ephemeris — the engine’s computed planetary facts — and rewritten if they contradict it. This checks the writing against the calculations; it does not establish astrology as a scientific prediction.
Where does my information go?
Your charts and calendar are calculated on your phone. When you ask for a letter, the service receives derived sky facts, your name and any words you supply. The app privacy policy explains these requests, birthplace search, purchases and crash reporting. The optional launch email list is separate from your app data. Read the app privacy policy.
Tandem offers a reflective practice. It does not predict outcomes or replace therapy, crisis support, or professional health, financial or legal advice.