Comparison

Abacus Lesson vs Flash

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

Head to head
About

Abacus Lesson

Learn the simple and fast method of division using an abacus. This app focuses on developing mental calculation skills by leveraging the abacus technique. It's recommended to master addition, subtraction, and multiplication with an abacus first.

Highlights
  • Learn abacus division techniques
  • Develop mental calculation skills
  • Focus on Soroban method
  • Step-by-step division instruction
  • Builds on addition, subtraction, multiplication
Features
Read full description

An abacus is named "Soroban" in Japan. Do you know what an abacus is? The abacus is very simple calculator used in China, Japan, Korea and so on. Some people may say "Isn't it an unnecessary tool if you have a calculator such as a smartphone?". Answer would be "No". The biggest difference between electric calculators and the abacus is whether you need to hold it in your hand when calculating. Because of its simplicity, you will be able to easily use the abacus in your mind. In the app, we will explain simple and fast method of the division using the abacus. To learn division, it is essential to be able to add, sub, and multiplication with an abacus. If you are new to them, we recommend that you learn addition subtraction multiplication with the app in my app list first. This app will give you the skill of calculation of division.

About

Flash

Features
Read full description

Train your mental arithmetic with numbers that flash one at a time. Watch the sequence, add it in your head, and enter the total before the next round. Flash keeps practice simple: • Choose 1–7 digits and 2–500 numbers. • Set the display speed from 0.1 to 3.0 seconds. • Practice 1–999 rounds or keep going in Infinite mode. • Turn answer input and automatic continuation on or off. • Choose a light or blue background. • Use sound, haptic, or both for feedback. • Save your favorite settings as presets. • Check accuracy, response time, streaks, and total training time. • Review the exact number sequence for each round and retry mistakes. Use it for a quick session or a longer challenge. Flash gives you a clear way to practice at your own pace.

Screenshots

Abacus Lesson3 screens
Flash4 screens

Verdict

The call

The clearest difference is in-app purchases: Flash at none against Abacus Lesson's 3. Flash also leads on ads (none vs shown). Abacus Lesson's advantage is update cadence (monthly vs every 4 months) and iOS requirement (11.0 vs 17.0). On price 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. Abacus Lesson sells 3 one-off in-app purchases. Flash asks for nothing beyond the download.

UpkeepUpdate frequency

Abacus Lesson ships an update monthly, Flash every 4 months. The most recent releases landed on September 21, 2026 and September 18, 2026 respectively.

Scorecard4 real differences · 6 level
Abacus Lesson versus Flash: the parameters behind the verdict, then further details
ParameterAbacus LessonFlash
PriceFreeFree
Rating5.0 (8 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings8 — better—
Update frequencyMonthly — betterEvery 4 months
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS11.0 — better17.0
Further details — not scored
Size132 MB16 MB
Age rating4+4+
DeveloperHirokazu Komatsuyeeun seo

In-app purchases

3 purchases

Abacus Lesson

One-time3
  • Donation Lv1 for hiding Ad$1.99
  • Donation Lv2 for hiding Ad$3.99
  • Donation Lv3 for hiding Ad$8.99
None

Flash

No in-app purchases

Questions

Is Abacus Lesson free?
Abacus Lesson is free to download, with in-app purchases available.
Is Flash free?
Flash is free to download, with no in-app purchases.
Do Abacus Lesson or Flash have ads?
Abacus Lesson shows ads; Flash does not.
Which is updated more often, Abacus Lesson or Flash?
Abacus Lesson ships an update monthly, and Flash every 4 months. Most recently, Abacus Lesson was updated on September 21, 2026 and Flash on September 18, 2026.

Other comparisons