Launching on iOS and Android
Every converter you'll ever need. Offline.
ZipSync replaces a folder of single-purpose apps. Discounts, tips, currency, kitchen measures, loans, time zones and more — in one fast app that works with no signal and no account.
- 56currencies, offline
- 17unit categories
- 300ingredient swaps
- $29.99 − 40%$17.99
- $86.40 ÷ 4$21.60
- 2 cups flour240 g
- 100 USD¥15,340
- 72°F22.2°C
- 6 ft 3 in190.5 cm
What's inside
One download replaces a folder of apps.
Six tabs hold everything you actually reach for — and all of it works without a connection, an account, or a sign-up screen.
Deals
"40% off" stops being a guess
Every price question you get asked in an aisle or at a table.
- Discount
- Second markdown
- Sales tax
- Tip split
- % change
- Reverse %
Convert
17 unit categories, 56 currencies
Length, weight, volume and temperature free forever. Exchange rates cache to your device, so conversion keeps working on a plane.
- Length
- Weight
- Volume
- Temperature
- Area
- Speed
- Time
- Data
- Energy
- Pressure
- Power
Kitchen
Cups to grams before the butter melts
Real per-ingredient weights rather than a generic ratio, because a cup of flour and a cup of honey don't weigh the same.
- Cups → grams
- Ounces
- Tablespoons
- Measure-it-out
- 300 swaps
Money
Loans, wages and real cost per mile
The slower arithmetic you'd otherwise open a spreadsheet for.
- Loan payment
- Compound interest
- APR → APY
- Hourly → yearly
- Cost in work-hours
- Gas vs electric
Ask AI
The impossible everyday questions
How many football fields tall is the Eiffel Tower? Bring your own free API key — it stays encrypted on your device, and Ask AI is never locked behind Premium.
- OpenAI
- Anthropic
- Always free
Private
No account. No sign-up. Offline.
History, preferences and your API key live on your device and are deleted when you uninstall.
- No login
- No tracking SDKs
- Works offline
- Gone on uninstall
Drawn to scale
Answers you can see.
Four real calculations, drawn rather than described. Every bar is the arithmetic, at the size the arithmetic actually is.
Kitchen
One cup. Three very different weights.
- Flour120 g
- Sugar200 g
- Honey340 g
Measured by volume they are identical. ZipSync weighs each ingredient properly.
Deals
See what you pay and what you keep.
Stack a second markdown on top, then add sales tax for the real out-the-door number.
Tips
Add the tip, then hand it round.
- $21.60
- $21.60
- $21.60
- $21.60
Any tip percentage, any number of people, down to the cent.
Time zones
Find the hours you both have free.
Three hours, both desks open — highlighted without you counting anything.
In practice
What people actually open it for.
Every one of these is a real calculation the app does — shown, not described.
Splitting a restaurant bill
Enter the total, pick a tip percentage, set the number of people. ZipSync returns the tip, the grand total and the exact amount each person owes.
$86.40 ÷ 4$21.60Working out a sale price in the aisle
Type the original price and the discount. You get the final price and the exact amount saved — plus an optional extra percentage off on top, and sales tax if you want the real out-the-door number.
$29.99 − 40%$17.99Converting cooking measurements mid-recipe
Convert any ingredient between cups, grams, ounces and tablespoons using real per-ingredient weights, because a cup of flour and a cup of honey do not weigh the same.
2 cups flour240 gConverting currency with no signal
ZipSync caches the latest rates for 56 currencies on your device, so conversions keep working on a plane or abroad without data.
100 USD¥15,340Checking a loan or savings payment
Calculate a monthly loan payment, model savings growth across daily, monthly, quarterly, annual or continuous compounding, and convert APR to the real APY yield.
$18,000 · 6.5% · 5 yr$352/moFinding a meeting time across time zones
Convert any city to any city and use the day-planner grid to see overlapping working hours at a glance.
9:00 AM PT5:00 PM GMTMeasuring for a home project
Feet and inches to metric and back, paint coverage, concrete slab volume, board feet for lumber, cabinet cut measurements, and inch fractions to millimetres.
6 ft 3 in190.5 cmPricing a purchase in work-hours
Turn a price into the thing it actually costs you: hours of your life. Enter your hourly rate and ZipSync tells you how long you'd work to pay for it.
$1,120 ÷ $28/hr40 hoursWorking out what a road trip costs
Trip cost from distance, fuel economy and pump price — plus cost per mile for petrol against electric, so you can settle which car to take.
300 mi · 32 mpg · $3.20$30.00
The brand
Small tools, built properly.
ZipSync makes the unglamorous apps you reach for without thinking — and tries to make them the best version of themselves: fast, private, and useful the moment you open them.
Offline first, not offline eventually
If a tool can work without a connection, it should. Rates cache, calculations run locally, and nothing waits on a server to give you an answer you could have had instantly.
No account, no sign-up
A calculator has no business knowing your email address. There is nothing to register for, nothing to remember, and nothing to leak.
Your data stays on your device
History, preferences and API keys live in encrypted device storage and are deleted when you uninstall. No analytics SDKs, no tracking, nothing sold.
Buy it once, or don't buy it at all
Where there's an upgrade it's a single one-time purchase, never a subscription — and the free version stays genuinely useful rather than crippled.
In development — sneak peek
Got 30 seconds? You've got a challenge.
A fresh challenge lands every day — quick, silly, creative, never the same twice. Complete it, earn points, keep your streak alive. In development now.
Join the waitlistOne challenge, start to finish
Four screens from the app, in the order you'd meet them. Swipe →
01Pick one
Pick a difficulty and go. One challenge, one tap, about thirty seconds.
02Prove it
Photo challenges want evidence. Every image is checked before it can be shared.
03Get paid
Finish and the points land on the spot. Watch an ad to double them, or go again tomorrow.
04Spin the wheel
Keep the streak and the wheel comes out. Twenty-four slots, three of them mystery.
A new challenge every day
About 30 seconds each. Quick enough to never skip.
- Pose
- Photo
- Answer fast
- Get moving
Snap it to prove it
Photo submissions build your own gallery.
- Safety-checked
- Private by default
Party with your friends
Take on the challenge together, then crown a winner.
- Invite friends
- Vote
- Bragging rights
Streaks that stick
Show up daily and watch it grow. Miss a day and tomorrow is right there waiting.
- Daily
- Never punishing
Points, ranks and rewards
Points climb the ladder — and they spend.
- Shop
- Prize wheel
- Plinko
Built kid-safe from day one
Family-facing from the ground up, not bolted on later.
- Parental consent
- Photo moderation
- No stranger chat
Climb the rank ladder
Every challenge earns points. Points move you up.
Bronze
Silver
Gold
Diamond
Masters
Legendary
Mythic
Pro
Coming soon
Be first into ZipSync Challenge Hub.
Be first in line the day it goes live on the App Store and Google Play — and we'll keep you posted on what ZipSync builds next.
- First to know when Challenge Hub launches
- New releases, product updates and occasional offers
- Unsubscribe in one click from any email
- We never sell or share your address
Questions, answered.
Is ZipSync free?
Yes. ZipSync is free to use and supported by a single small banner ad. Free users also get ten Premium-tool uses every day, so you can try everything before deciding whether to upgrade.
Is Premium a subscription?
No. ZipSync Premium is a one-time purchase with no subscription and no login. It is tied to your App Store or Google Play account, follows you to new devices, and Restore Purchase is always available.
What does Premium unlock?
Premium removes all ads permanently and unlocks every Pro tool — time zones, construction, banking and loans, wage and salary, driving and fuel — plus the full 300-ingredient substitution library, D&D dice from d4 to d20, and custom counter styles.
Does ZipSync work offline?
Yes. Every calculator and unit conversion works fully offline, and currency rates are cached to your device so conversions keep working without a connection. Only refreshing exchange rates, refreshing inflation data and using Ask AI require internet.
Do I need an account to use ZipSync?
No. ZipSync has no login, no registration and no sign-up. It never asks for your name, email or phone number.
What units can ZipSync convert?
Seventeen unit categories in all. Length, weight, volume and temperature are free. Area, speed, time, data, energy, pressure, power, angle, torque, frequency, density, force and flow rate are included with Premium, and fuel economy lives in the Driving tool. Currency covers 56 world currencies, and kitchen conversions use real per-ingredient weights.
How does Ask AI work, and does it cost extra?
Ask AI is always free and never locked behind Premium. You supply your own free API key from OpenAI, Anthropic or Google. The key is stored encrypted on your device, and your questions go directly from your device to the provider you chose — the developer never receives or stores them.
What data does ZipSync collect?
Your age, history, saved items, preferences and any AI API key stay on your device and are deleted when you uninstall. The only data that leaves your device is what Google AdMob collects to serve ads, plus anything you send through Ask AI using your own key. There are no analytics or tracking SDKs beyond the ad network, and no data is ever sold.
Why does ZipSync ask my age?
It is asked once and stored encrypted on your device to decide whether ads can be personalised, in line with COPPA and GDPR-K. It is never transmitted anywhere. Users under 16 see only non-personalised ads.
Which platforms is ZipSync available on?
ZipSync is built for iPhone and Android. It is launching on the App Store and Google Play.
What is ZipSync Challenge Hub?
ZipSync Challenge Hub is an upcoming app that gives you one fresh challenge every day, designed to be completed in about 30 seconds. You earn points, build a streak, climb a rank ladder, and can create parties with friends to take on challenges together and vote on the best submission.
When is ZipSync Challenge Hub coming out?
It is in development and does not have a public release date yet. Join the waitlist on this page and we will email you when it launches, along with occasional news about new ZipSync releases, updates and offers. You can unsubscribe from any email.
Is ZipSync Challenge Hub safe for kids?
It is designed for families from the ground up: parental consent for younger players, photo moderation before any image is shared, no chat with strangers, and privacy-first settings by default. The waitlist itself is limited to people aged 16 and over.