SPIDERPLUS for iPhone vs Duct
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SPIDERPLUS for iPhone
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----What is SPIDER PLUS?---- SPIDER PLUS is a field work management and information sharing system specialized in the construction industry. Features *Download and store a large quantity of drawings data in a tablet PC and no need to carry around paper drawings. *Attach memos and photos on the drawings at the field. *There is a folder function similar to Windows Explorer, and thumbnail images are also displayed and desired drawings can be easily found. *Approximate distance can be measured through a scale function. *Drawings and photos turned into PDF files on an iPad can be mailed directly without going through a server. *Share information among users in real-time. *Memos and photos can be output as EXCEL/PDF report. ----How to use SPIDER PLUS?---- 1. Register drawings on the server 2. Download to mobile devices from the server and carry around 3. Attach memos and photos on the drawings at the field 4. Share information among users in real-time 5. Edit and output contents entered from mobile devices using a web browser.
Duct
This application simplifies the selection of duct sizes using intuitive design and simple operations. It calculates appropriate duct sizes based on airflow, standard static pressure, and air velocity, supporting both rectangular and round ducts.
- Intuitive design for easy duct size selection
- Calculates duct size based on airflow, static pressure, and velocity
- Supports both rectangular and round ducts
- Visual representation of selected duct shapes
- Customizable warning and upper limits for aspect ratio and air velocity
- Set default standard static pressure
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『Duct-Fit』は、直感的に分かりやすいデザインと単純な操作で、ダクトサイズを選定出来るアプリです。 「風量」「基準静圧」「風速」を基に適正なダクトサイズの算出が可能です。 特徴 ・選定したダクト形状を図形で表示することにより、ダクトイメージが付きやすい設計になっています。 ・「角ダクト」だけでなく「丸ダクト」のダクトサイズ算出にも対応してます。 ・「アスペクト比」や「風速」に目安となる「警告値」を任意で設定できます。 ・「アスペクト比」や「風速」に計算可能な上限としての「上限値」を任意で設定できます。 ・「基準静圧」は「初期値」として任意で通常使う値を設定することができます。 ・ダクトサイズの選定については、「コールブルックの式」及び「ダルシー・ワイズバッハ式」により、選定しております。
Screenshots
Verdict
The clearest difference is update cadence: SPIDERPLUS for iPhone at every 5 weeks against Duct's every 16 months. Duct's advantage is device support (3 vs 1) and iOS requirement (11.4 vs 17.0). On price, ads and in-app purchases 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.
SPIDERPLUS for iPhone ships an update every 5 weeks, Duct every 16 months. The most recent releases landed on September 20, 2026 and October 6, 2026 respectively.
| Parameter | SPIDERPLUS for iPhone | Duct |
|---|---|---|
| Price | Free | Free |
| Positive reviews | — | 100.0% of reviews |
| Update frequency | Every 5 weeks — better | Every 16 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | — | Free |
| Devices | iPhone | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 11.4 — better |
| Further details — not scored | ||
| Size | 54 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | SpiderPlus & Co. | Izumi Consulting,Inc. |
In-app purchases
SPIDERPLUS for iPhone
No in-app purchases
Duct
No in-app purchases









