Time Delay calculator vs Rub Memo
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Time Delay calculator
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A calculator that can display calculation results with a delay to practice mental arithmetic. >Mental arithmetic practice mode Tap the timer key to turn on mental math practice mode. Enter the formula as usual. *Tap the timer key again to turn off the mental arithmetic practice mode. Return to normal calculator mode.
Rub Memo
This app allows you to erase text by rubbing your finger over it, mimicking the feel of erasing pencil on paper. It also offers a home screen widget for quick access, reordering paragraphs, and inserting various media like tables, checklists, and drawings.
- Erase text with finger rub
- Home screen widget for notes
- Reorder paragraphs by long-press and drop
- Insert tables, checklists, images, and drawings
- Full-text search with highlighted matches
- Lock notes with Face ID/Touch ID
- Export and share as PDF
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■ Rub to erase Turn on the "Eraser" in the toolbar and just rub your finger over the text you want gone. Characters fade away one by one — no selecting and deleting. It feels like rubbing out pencil on a paper notebook, right on your phone. ■ Home Screen widget Your most recent note appears in a Home Screen widget. Tap it to jump straight back in. ■ More features ・Long-press a paragraph to lift it, then drop it anywhere to reorder ・Insert tables, checklists, images, and finger drawings (you can erase those too) ・Full-text search with highlighted matches ・Lock individual notes with Face ID / Touch ID ・Export and share as PDF ・Switch between Japanese and English ・Adjust font size, font, ruled lines, and eraser width ■ No ads, no in-app purchases, no sign-up, no data collection. All your data stays on your device.
Screenshots
Verdict
The clearest difference is ads: Rub Memo at none against Time Delay calculator's shown. Rub Memo also leads on update cadence (every 6 days vs fortnightly). Time Delay calculator's advantage is device support (3 vs 1). On price, in-app purchases and iOS requirement 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
Both are free to download. Neither carries in-app purchases, so what you see is what you pay.
Time Delay calculator ships an update fortnightly, Rub Memo every 6 days. The most recent releases landed on October 6, 2026 and September 23, 2026 respectively.
| Parameter | Time Delay calculator | Rub Memo |
|---|---|---|
| Price | Free | Free |
| Positive reviews | — | 100.0% of reviews |
| Update frequency | Fortnightly | Every 6 days — better |
| Ads | Yes | No — better |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPhone, iPad, iPod — better | iPhone |
| Requires iOS | 15.8.3 — better | 16.0 |
| Further details — not scored | ||
| Size | 36 MB | 14 MB |
| Age rating | 4+ | 4+ |
| Developer | Hideaki Uchikoshi | seiji honda |
In-app purchases
Time Delay calculator
No in-app purchases
Rub Memo
No in-app purchases
Questions
Is Time Delay calculator free?
Is Rub Memo free?
Do Time Delay calculator or Rub Memo have ads?
Which is updated more often, Time Delay calculator or Rub Memo?
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