Grows with your steps
Egg to monster,
one walk at a time
Mosskip hatches, then evolves through stages as you walk. Your movement literally shapes him.
Meet your
reluctant
fitness buddy
Walk a little. Grow together. He complains the whole way.
Grumble turns your daily steps into a creature called Mosskip — who refuses to be impressed, and slowly grows into something larger anyway. It reads your step count from Apple Health and gets on with it.
Get Grumble
Free on the App Store
iPhone · iOS 15.1 or later
- No account, ever
- Health data stays on your phone
- Not a subscription
He says things like
- “i do not know how to be useful yet.”
- “Carries anything. Defeated by stairs.”
- “still getting to know you.”
- “Hatched today. Still slightly damp.”
What it does
No streaks to protect. No guilt if you stop. Just a small animal keeping score, badly.
Egg to monster,
He remembers
Your habits become
his personality
A shared history that keeps the walks worth keeping — and the days you skipped, without comment.
A weekly look back
The week you had,
not the one you meant
A short report every Monday. Honest about the quiet days, generous about the rest.
- Live sessionsStart a walk and watch it tick along on the Lock Screen and in the Dynamic Island.
- Log anythingRuns, the gym, whatever else. Not everything worth doing shows up as steps.
- Never scolds youGrumpy, slightly goofy, and completely uninterested in shaming you into a walk.
He remembers
every walk you take
Every stage, every quiet week, every time you came back after stopping. Mosskip keeps the record — not as a streak to break, but as a shared history worth having.
- 4stages, from egg to Grumbeast
- 2things read from Apple Health
- 0accounts, ads or analytics
Grumble Pro
Grumble is free, and stays useful for free. Later monster stages are unlocked by Pro — a one-time purchase. Not a subscription. It does not renew, and it will not charge you again.
$6.99
USD · once
Early access
- Youngling and Grumbeast — the later monster art
- Everything you already had, permanently
- No renewal, no second charge, no upsell later
How Grumble is sold to new users may change later — the price, or the one-time purchase itself. What cannot change is a purchase already made: everything included in Pro at the time you bought it stays yours, permanently and at no further cost. That commitment is written into the Terms, not just implied here.
Privacy, briefly
It reads two things,
It reads two things,
and nothing else
- Step count
- Walking & running distance
- Not heart rate, not workouts, not location
Access is read-only, and the data is never transmitted anywhere. The only information that ever leaves your phone is what's needed to process a purchase. Full detail in the Privacy Policy.
Go on. Give Mosskip a poke.
He will pretend not to enjoy it.
Download on the App StoreFree · iPhone · iOS 15.1 or later