Selfie at the rack. Heart rate window. Done in under 30 seconds.
- Live photo
- HR sustained 6 min+
- Active energy +120 kcal
INVITE-ONLYINDIA · 202647 / 200 SEATS
ONE STREAK.
THE WHOLE SQUAD.
GRIND is a fitness app where 3-10 friends share a single daily streak. Skip a day, the squad's streak dies. Fake a check-in, the squad BOOMs you.
Free during prototype. No card. No paywall hidden anywhere.
SQUAD STREAK
47DAYS
SQUAD · 5/5 IN
CHECK-IN MODE
GYMHOMEWALK
VERIFIED · 4 SIGNALS
Live photo · captured in-app
GPS · Lower Parel, Mumbai
Motion · 8 min sustained
HealthKit · 182 kcal active
PASSSTREAK SECURED
ONE CHECK-IN A DAY.
THAT'S THE WHOLE APP.
Three modes. Pick one. Do it before midnight. The squad sees the verdict in real-time.
MODE 01GYM MODE 02HOME Live photo mid-rep. Motion data tracks the set. Works without equipment.
- Live photo
- IMU motion pattern
- Stand minutes
MODE 03WALK GPS route + distance + steps + active calories. Open-air or treadmill.
- GPS route
- Distance ≥ 1km
- Steps ≥ 1500
IT'S NOT YOUR STREAK.
IT'S THE SQUAD'S.
One person flakes Tuesday, everyone wakes up Wednesday on Day 0. That's the deal. That's why it works.
47DAYS
SQUAD · 5/5 IN
5 of 5 checked in. The squad streak is on Day 47. Nobody has to lift today — except themselves.
- Squads of 3-10. Invite-only. Friends only.
- One miss = full squad reset. No grace days in Beast mode.
- Strictness levels: Chill (3/wk), Strict (5/wk), Beast (6/wk).
YOU CAN'T FAKE THE CHECK-IN.
WE'VE TRIED.
Every check-in cross-checks four signals on your phone. If the story doesn't match, it's flagged before your squad even sees it.
A fake check-in tries to land.
Submitted by VIKRAM_D · claim: "ran 5K in Aarey forest"
- LIVE PHOTO…
Waiting for signal…
- GPS…
Waiting for signal…
- MOTION…
Waiting for signal…
- HEALTH…
Waiting for signal…
VERDICT…
The squad never sees this submission. The engine flagged it before they got a notification.
SIGNAL 01LIVE PHOTO Camera opens in-app. Gallery upload is blocked at the system level.
FAIL · Screenshot of an old gym selfie → blocked before submit.
SIGNAL 02GPS Your location at the moment of capture. Cross-checked against your mode.
FAIL · GPS says home, mode says gym → flagged.
SIGNAL 03MOTION Your phone’s IMU during the set. Detects movement type and duration.
FAIL · Phone sitting on a table while "doing pushups" → flagged.
SIGNAL 04HEALTH Derived signals from HealthKit / Health Connect. Raw data never leaves your phone.
FAIL · Claims a 5K run. Heart rate stayed at 60bpm the whole hour → flagged.
PRIVACY · ON-DEVICE FIRST
Raw HealthKit / Health Connect data never leaves your phone. GRIND only receives derived booleans — "did a workout happen in the last 90 minutes: yes/no" — not your heart rate, not your sleep, not your steps.
WHEN YOUR SQUAD
SMELLS A FAKE — BOOM.
If a check-in feels off, anyone in the squad can BOOM it. 12-hour vote. Majority decides. Public record.
- L1
Lazy fake
Mild call-out. Logged to your squad's history.
- L2
Repeat or obvious cheat
Public Crime Board entry. Visible across all squads.
- EPIC
Premeditated with receipts
Hall of Infamy. Permanent file. Doesn't go away.
CRIME BOARD · LIVE
Today's calls.
Hover any card to BOOM it yourself. Click triggers a severity vote. This is a sandbox — no one's actually getting BOOMed.
gym selfie at 11:54 PM, mirror angle suspicious
GPS says home, photo says gym
same shirt as Tuesday — fake check-in?
no sweat. no breath. no proof.
treadmill display showed 0:00
background looks like flat, not gym
claims 5K but heart rate flat
weights in foreground, never lifted
mirror crack matches Monday’s photo
story posted from couch 2m later
GPS jumped 12km in 3 minutes
photo metadata says yesterday
THE BOARD
REMEMBERS.
said ‘busy’ Wednesday — squad found his story at the bar
sent the same gym selfie three Mondays in a row
GPS at the gym, phone at home
check-in at 6 AM. tagged at brunch by 7.
told the squad it was a sprint. AirTag said couch.
WHAT WE SEE.
WHAT WE DON'T.
You're giving the app camera and health permissions, and inviting friends. Here's the honest version, written before any paid privacy review.
- PHOTOS
Live capture only. Stripped of EXIF metadata. Encrypted at rest. Auto-deleted after 90 days.
- HEALTH DATA
Stays on your device. We receive derived booleans, never raw heart-rate streams or workout objects.
- YOUR SQUAD
You control who's in. Invite by phone contact or share code. You can leave any squad anytime.
- YOUR ACCOUNT
Delete in-app, 30-day grace, then full wipe. Export your data on request. India-hosted (DPDP-aligned).
BUILT FOR.
You, if
- People who've quit 3+ fitness apps this year.
- Friend groups that already roast each other in WhatsApp.
- Urban India. Hinglish welcome. No oiled-torso vibe.
- Anyone who's faked a check-in. You know who you are.
Not you, if
- Solo grinders who hate accountability.
- People who want a coach, meal plan, or trainer (we don't do that).
- Anyone who can't take a public roast from their own squad.
- Cheaters. The engine will catch you, then your friends will.
200 SEATS.
INVITE-ONLY.
ZERO RUPEES.
The Founding 200 get GRIND free during the prototype. India only for now. We onboard in cohorts of ~50.
200 SEATS. 47 LEFT. PROTOTYPE COHORT.
- No paid tier exists yet. You won’t be charged.
- Onboarded in cohort drops of ~50. iOS first.
- Founding 200 keep early-access status forever.
Free. No card. India launch 2026.
ASKED EARLY.
ANSWERED EARLY.
What does GRIND cost?
Free during the Founding 200 prototype. No card needed, no paywall hidden anywhere. When we eventually charge, you keep your early-access badge and we'll tell you the price before we charge a rupee.iOS or Android?
Both. iOS ships first because HealthKit is more mature than Health Connect. Android follows in the next cohort drop. If you're on Android, you'll get an invite in cohort 2.What if my friends won’t join?
You can join an existing 3-person squad looking for new members. We'll match by strictness level + city. You'll never be alone in a squad of one.Can I appeal a BOOM?
In the prototype, the squad vote is final. We track repeat false BOOMs and can demote serial offenders. If you think your squad's ganging up unfairly, you can leave the squad anytime.What happens to my photos?
Live capture only — gallery upload is blocked at the camera. Photos are stripped of metadata, encrypted at rest on Cloudflare R2 (India region), and auto-deleted after 90 days. BOOM evidence photos clear 30 days after the vote resolves.What does HealthKit data look like to GRIND?
We only see derived booleans: workout_detected: true, active_energy_kcal_window90: 182. Raw heart rate, workout sessions, sleep data — none of that ever leaves your phone.What happens after the Founding 200?
Cohort 2 opens late 2026. Founding 200 keep early-access status forever, get to vote on which features ship first, and skip future waitlists for related products.