RC Circuit vs HSA
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
RC Circuit
Calculate RC charging and filter circuits, including time constants and cutoff frequencies. Find component values from these parameters or get voltage at specific times. Save and share data easily.
- Calculate time constant
- Find component values
- Get voltage at time t
- Calculate cutoff frequency
- Save data to CSV
- Upload CSV via AirDrop/iCloud Drive
- Multi-language support
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This app is used to calculate the RC charging and RC filter circuit. It is suitable for hobbyist or electronic engineer. Features * Calculate time constant from R, C * Find component value R,C from time constant * Get voltage at time t in RC charging / discharging * Calculate cutoff frequency by R, C * Find component value R,C from cutoff frequency * Save data to CSV files * Upload CSV via AirDrop / iCloud Drive * Support English, Traditional Chinese, Simplified Chinese, German, French, Italian, Spanish, Portuguese, Japanese
HSA
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-4 CH Professional Car DSP, tuning up by Phone APP
Screenshots
Verdict
The clearest difference is in-app purchases: HSA at none against RC Circuit's 1. HSA also leads on update cadence (every 2 months vs every 6 months) and iOS requirement (8.0 vs 12.0). On price, 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
Both are free to download. RC Circuit sells 1 one-off in-app purchase. HSA asks for nothing beyond the download.
RC Circuit ships an update every 6 months, HSA every 2 months. The most recent releases landed on October 5, 2026 and October 7, 2026 respectively.
| Parameter | RC Circuit | HSA |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (5 ratings) — better | — |
| Number of ratings | 5 — better | — |
| Update frequency | Every 6 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPod |
| Requires iOS | 12.0 | 8.0 — better |
| Further details — not scored | ||
| Size | 16 MB | 10 MB |
| Age rating | 4+ | 4+ |
| Developer | Siu Yuen Ho | 杏生 卢 |
In-app purchases
RC Circuit
- Unlock Pro features$0.99
HSA
No in-app purchases
