Timer 555 Calculator Pro Downloads & RevenueTimer 555 Calculator Pro · App Store
Not in any tracked top chart right now.
Updated 8 Nov 2026 · rankings refresh through the day
DeveloperSiu Yuen Ho
CategoryUtilities
Price0.99 USD
Released
Rating★ 4.7 (3)
Version3.0.15
Age rating4+
First seen by us
24 Oct 2026
Timer 555 Calculator Pro update history & changes
Last change · 3 events since 6 Mar 2014Full timeline ↓Full timeline · 2 events in the last 12 months
- 🆕Timer 555 Calculator Pro first spotted by AppInsiderUnited States (found via developer)
- 🆕Timer 555 Calculator Pro released on the App Store
Collected from the stores by AppInsider since we first spotted the app. Dates are when we saw each change.
Rating
4.7 ★
3 ratings
Measured
Timer 555 Calculator Pro on the App Store
App details
App ID
833443125
Publisher
Siu Yuen Ho
On the store since
Mar 2014
12 years on the store
Minimum OS
iOS 13.2+
iPhone 6s and later
Devices
iPhone · iPad
Universal purchase
Content rating
4+
Languages
12
EN FR DE HI IT JA KO PT RU ZH ES ZH
Size
3 MB
Where it ranks now
Every top chart it appears in across 30 countries.
| Country | Charts | Rank |
|---|---|---|
| Not charting right now. | ||
Ratings
App Store, worldwide.
Rating
4.7 ★
3 ratings
Measured
Ratings
3
Measured
About Timer 555 Calculator Pro
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
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 updates
3.0.15
Fix minor bugs