Apps by Siu Yuen Ho
Timer 555 Calculator Pro app icon

Utilities

Timer 555 Calculator Pro

Siu Yuen Ho

$0.99 4.67 · 1 storefront · 3 ratings In-app purchases unconfirmed
Open on Apple

About this app

This app is used to calculate monostable and astable circuit. Features * Calculate pulse width of monostable circuit * Calculate frequency of astable circuit * Find out combination of components making a desire pulse width in monostable circuit * Find out combination of components making a desire frequency in astable circuit * Share file to iCloud Drive (For iOS8 or later) * Share file via AirDrop Additional Features in the Professional Edition * Unlimited number of combinations * Allow to change tolerance * No ads

Latest release

What’s New

Version 3.0.15 Mar 25, 2024

Fix minor bugs

Audience growth

Ratings growth

Steady
7-day gain +0
Ratings / day 0.0
30-day gain +0
US rating-count history
3 ratings
3 Aug 26, 2026 · 3 ratings Aug 26, 2026

Baseline captured. Growth appears after the crawler observes a changed rating count.

Momentum comes from crawler snapshots for the tracked storefront. “Viral growth signal” means unusually fast recent rating gains; it is an indicator, not download data.

Price tracking

Price intelligence

1 captured event
Current $0.99
Historical low USD 0.99
Paid → free
Price history
Current $0.99
$0.99 $0.50 Free Aug 26, 2026 · $0.99 Aug 26, 2026

First snapshot captured. The trend line starts after the next crawler price observation.

  1. First observed Aug 26, 2026 · 8:27 AM $0.99

Screenshots

Timer 555 Calculator Pro iPhone screenshotTimer 555 Calculator Pro iPhone screenshotTimer 555 Calculator Pro iPhone screenshotTimer 555 Calculator Pro iPhone screenshotTimer 555 Calculator Pro iPhone screenshot Timer 555 Calculator Pro iPad screenshotTimer 555 Calculator Pro iPad screenshotTimer 555 Calculator Pro iPad screenshotTimer 555 Calculator Pro iPad screenshotTimer 555 Calculator Pro iPad screenshot