Comparison

Houji vs Bolt Length

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head

Calculate screw length

Free

📊 Productivity

★ 3.02 ratingsView app →

About

Houji

Features

Read full description

houji is japanese custom. This App calculate houji_days.

About

Bolt Length

This application helps calculate the length of metric coarse screws based on Japanese Industrial Standards. It is designed for mechanical design purposes and should be used at the user's own risk.

Highlights

Metric coarse screw length calculation
Conforms to Japanese Industrial Standards (JIS)
Designed for mechanical design
User risk disclaimer

Features

Read full description

This app is an application for calculating the length of the screw. ※:This app does not guarantee the effectiveness of the combination. ※:Use this application at your own risk. Conforms to the Japanese Industrial Standards (JIS). Screws are all metric coarse screw. For mechanical design. Sorry, Only in Japan.Because using the JIS.

Screenshots

Houji4 screens

Bolt Length4 screens

Verdict

The call

The clearest difference is price: Bolt Length at Free against Houji's $1.99. Bolt Length also leads on device support (3 vs 1) and iOS requirement (14.0 vs 16.1). Houji's advantage is in-app purchases (none vs 1) and ads (none vs shown).

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Bolt Length is free to download; Houji costs $1.99 up front. Bolt Length sells 1 one-off in-app purchase. Houji asks for nothing beyond the download.

UpkeepUpdate frequency

Houji ships an update every 7 months, Bolt Length every 20 months. The most recent releases landed on November 1, 2026 and November 2, 2026 respectively.

Scorecard6 real differences · 4 level

Houji versus Bolt Length: the parameters behind the verdict, then further details
Parameter	Houji	Bolt Length
Price	$1.99	Free — better
Rating	—	3.0 (2 ratings) — better
Positive reviews	—	33.3% of reviews
Number of ratings	—	2 — better
Update frequency	Every 7 months — better	Every 20 months
Ads	No — better	Yes
In-app purchases	No — better	Yes
Monetization	—	Free with in-app purchases
Devices	iPhone	iPhone, iPad, iPod — better
Requires iOS	16.1	14.0 — better
Further details — not scored
Size	4 MB	6 MB
Age rating	4+	4+
Developer	her0.jp	mitsunori oishi

In-app purchases

None

Houji

No in-app purchases

1 purchases

Bolt Length

One-time1

Hide Ads$1.99

Questions

Is Houji free?

Houji costs $1.99, with no in-app purchases.

Is Bolt Length free?

Bolt Length is free to download, with in-app purchases available.

Do Houji or Bolt Length have ads?

Bolt Length shows ads; Houji does not.

Which is updated more often, Houji or Bolt Length?

Houji ships an update every 7 months, and Bolt Length every 20 months. Most recently, Houji was updated on November 1, 2026 and Bolt Length on November 2, 2026.