Comparison

OffOf vs Odometer Data Observer

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

OffOf

This app simplifies percentage calculations for shopping discounts and finding a percentage of a number. It offers a clean interface with satisfying sound and haptic feedback for a delightful user experience.

Highlights
  • Calculate percentage OFF
  • Calculate percentage OF
  • Shopping discount calculations
  • Mechanical keyboard sounds
  • Haptic feedback
Features
Read full description

A beautiful percentage calculator. OffOf helps you calculate to percentage OFF of a particular number, and the percentage OF a particular number. OffOf is NOT a full calculator. Your device already comes with a great calculator. OffOf is a Percentage Calculator ONLY. • 35% OFF Instantly know how much you're going to spend while shopping. What is the cost of that $18.99 t-shirt when its 35% off? OffOf makes it easy to calculate. Simply enter 35% as the "Percentage" and 18.99 as the "Amount" and OffOf will show you how much you'll be spending after the discount. • 16% OF What is 16% of 2,458? OffOf will get you that answer instantly. Just enter 16% as the "Percentage" and 2,458 as the "Amount" and you'll know right away. • Real, satisfying mechanical keyboard sounds • Delightful haptic feedback on button presses and more

About

Odometer Data Observer

Features
Read full description

ODO stands for Odometer Data Observer. It was built for people who rely on their cars every day, but don’t want to spend their time thinking about maintenance dates, kilometres, paperwork, or “did I forget something?” moments. ODO quietly keeps track of everything that matters: services, mileage, events, receipts, and ownership history all in one place, across one or multiple cars. No spreadsheets. No guesswork. No stress. Unlike traditional car apps, ODO adapts to you. You choose how involved you want to be, how often you’re reminded, and what matters most. ODO handles the rest in the background. Because car ownership shouldn’t feel like admin. It should feel reliable, organised, and out of your way. Just enjoy the road. ODO takes care of the rest. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

OffOf3 screens
Odometer Data Observer4 screens

Verdict

The call

The clearest difference is price: Odometer Data Observer at Free against OffOf's $0.99. Odometer Data Observer also leads on update cadence (every 5 days vs every 59 months). OffOf's advantage is in-app purchases (none vs 10) and device support (5 vs 2). On ads there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Odometer Data Observer is free to download; OffOf costs $0.99 up front. Odometer Data Observer sells 10 in-app purchases, starting at $2.99 per month. OffOf asks for nothing beyond the download.

UpkeepUpdate frequency

OffOf ships an update every 59 months, Odometer Data Observer every 5 days. The most recent releases landed on September 22, 2026 and September 13, 2026 respectively.

Scorecard5 real differences · 5 level
OffOf versus Odometer Data Observer: the parameters behind the verdict, then further details
ParameterOffOfOdometer Data Observer
Price$0.99Free — better
Rating4.6 (11 ratings) — better—
Positive reviews60.7% of reviews—
Number of ratings11 — better—
Update frequencyEvery 59 monthsEvery 5 days — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationFree—
DevicesiPhone, iPad, Mac, Apple Watch, Vision Pro — betteriPhone, iPad
Requires iOS17.2 — better26.2
Further details — not scored
Size5 MB4 MB
Age rating4+17+
DeveloperDaeo Corp. SoftwareSotiris Sotiriou

Bugs and requests

OffOf

Reported bugs

3 issues
  • Not compatible with new iOS updates
  • App no longer opens/works
  • Freezes and force closes

Requested features

5 requests
  • Make it a fully functional calculator
  • Update to new software/iOS versions
  • Show final price after discount
  • Auto clear fields on tap
  • Update for X screens

Odometer Data Observer

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

OffOf

No in-app purchases

10 purchases

Odometer Data Observer

Subscriptions10
  • 1 ADDITIONAL CAR (Monthly)$2.991 Month
  • COST MANAGEMENT (Monthly)$2.991 Month
  • BASIC (Monthly)$4.991 Month
Show 7 more
  • 2 ADDITIONAL CARS (Monthly)$4.991 Month
  • 3 ADDITIONAL CARS (Monthly)$7.991 Month
  • 1 ADDITIONAL CAR (Yearly)$24.991 Year
  • COST MANAGEMENT (Yearly)$24.991 Year
  • BASIC (Yearly)$49.991 Year
  • 2 ADDITIONAL CARS (Yearly)$49.991 Year
  • 3 ADDITIONAL CARS (Yearly)$79.991 Year

Questions

Is OffOf free?
OffOf costs $0.99, with no in-app purchases.
Is Odometer Data Observer free?
Odometer Data Observer is free to download, with in-app purchases available.
Do OffOf or Odometer Data Observer have ads?
Neither OffOf nor Odometer Data Observer shows ads.
Which is updated more often, OffOf or Odometer Data Observer?
OffOf ships an update every 59 months, and Odometer Data Observer every 5 days. Most recently, OffOf was updated on September 22, 2026 and Odometer Data Observer on September 13, 2026.

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