Comparison

AddCalculator vs Useful Lock Screen Memo

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

Head to head
About

AddCalculator

This utility automatically sums numbers as you input them, streamlining quick calculations. Create custom buttons for frequently used values and review your calculation history. It offers undo/redo functionality and supports two color themes for a personalized experience.

Highlights
  • Automatic addition on number press
  • Customizable number buttons
  • Calculation history log
  • Undo and redo functionality
  • Dual color mode support
Features
Read full description

- Each time you press a number, it automatically adds up, allowing you to calculate the sum quickly. - You can create a button by specifying the number you want. - You can check the history of calculated numbers at any time. - You can undo and redo. - Supports two color modes.

About

Useful Lock Screen Memo

Features
Read full description

Keep what matters in sight, right on your Lock Screen. Useful Lock Screen Memo is a notes and reminders app that lets you check important notes and plans directly from your Lock Screen. Use Live Activities and widgets to display shopping lists, today’s tasks, things you need to remember and schedules you check often. 【Key features】 ■ Lock Screen notes Save a note to display it in a Live Activity and check it quickly from your Lock Screen. You can also adjust the text size and display color. ■ Reminder notifications Choose a date and time to receive the note text as a notification. You can also repeat reminders on selected days of the week. ■ Flexible advance alerts In addition to the scheduled time, enable any alerts you need: 3 days, 2 days, 1 day, 12 hours, 6 hours, 3 hours, 2 hours, 1 hour, 30 minutes, 15 minutes, 10 minutes, 5 minutes, 3 minutes or 1 minute beforehand. Use shared default settings or choose advance alerts individually for each reminder. ■ Manage multiple reminders See your saved reminders in a vertical list. If a notification cannot be scheduled, the app clearly marks it with a warning or an error. ■ Note and reminder history Previous Lock Screen notes and completed reminders are saved in history. Delete items you no longer need by swiping or pressing and holding. ■ Notification sound selection Choose from multiple built-in sounds to suit each occasion. ■ Lock Screen widget Add the widget to check a note or quickly open the app from your Lock Screen. 【Recommended for anyone who wants to】 ・Display a shopping list on your Lock Screen ・Avoid forgetting belongings or deadlines ・Check work or study plans frequently ・Receive several alerts for an important event ・Keep simple notes and reminders together in one app ・Check a note without opening the app 【Pricing】 All features are free. The app displays ads. With the optional one-time “Remove Ads” purchase, you can hide all ads. Even without “Remove Ads”, there are no feature restrictions. 【Before using the app】 ※ Live Activities and notifications must be allowed in your device settings, and the widget must be added to your Lock Screen. ※ The display duration and update timing of Live Activities may vary depending on iOS system conditions. ※ Requires iOS 26 or later. Created by katapu.net

Screenshots

AddCalculator3 screens
Useful Lock Screen Memo4 screens

Verdict

The call

The clearest difference is in-app purchases: AddCalculator at none against Useful Lock Screen Memo's 1. AddCalculator also leads on iOS requirement (17.0 vs 26.0). On price, update cadence, ads and device support 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

Both are free to download. Useful Lock Screen Memo sells 1 one-off in-app purchase. AddCalculator asks for nothing beyond the download.

UpkeepUpdate frequency

AddCalculator ships an update every 5 days, Useful Lock Screen Memo weekly. The most recent releases landed on October 4, 2026 and October 24, 2026 respectively.

Scorecard2 real differences · 6 level
AddCalculator versus Useful Lock Screen Memo: the parameters behind the verdict, then further details
ParameterAddCalculatorUseful Lock Screen Memo
PriceFreeFree
Positive reviews100.0% of reviews—
Update frequencyEvery 5 days — betterWeekly
AdsYesYes
In-app purchasesNo — betterYes
MonetizationAd-supported—
DevicesiPhoneiPhone, iPad — better
Requires iOS17.0 — better26.0
Further details — not scored
Size6 MB118 MB
Age rating4+4+
DeveloperMinseong Kimkatapu.net

In-app purchases

None

AddCalculator

No in-app purchases

1 purchases

Useful Lock Screen Memo

One-time1
  • Remove Ads$5.99

Questions

Is AddCalculator free?
AddCalculator is free to download, with no in-app purchases.
Is Useful Lock Screen Memo free?
Useful Lock Screen Memo is free to download, with in-app purchases available.
Do AddCalculator or Useful Lock Screen Memo have ads?
Both AddCalculator and Useful Lock Screen Memo show ads.
Which is updated more often, AddCalculator or Useful Lock Screen Memo?
AddCalculator ships an update every 5 days, and Useful Lock Screen Memo weekly. Most recently, AddCalculator was updated on October 4, 2026 and Useful Lock Screen Memo on October 24, 2026.

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