STP One - STEP 3D Viewer

STP One is a drawing viewer built for the shop floor: open STEP and IGES 3D files and 2D drawings (DXF) right on your phone. The overall size (W×D×H) appears as soon as a file opens, and measurement, section, parts and weight are all in one app.

■ 3D viewing
· Open STEP (.stp/.step) and IGES (.igs/.iges)
· One finger to rotate, two fingers to pan and zoom, [Fit] to recenter
· Overall dimensions shown automatically, plus approximate volume and surface area
· Edge highlight: normal → bold → hidden

■ Measurement (Pro)
· Point-to-point distance with ΔX · ΔY · ΔZ
· Point→edge perpendicular distance
· Face↔face distance between two parallel faces, with the angle between them

■ Section & parts (Pro)
· Section along X/Y/Z — move the slider to cut the model and see inside, flip direction
· Assembly parts list — each part cycles visible → transparent → hidden

■ Weight (Pro)
· 245 built-in materials (steel sheet, stainless steel, non-ferrous metals, spring wire, injection resins, rubber and more)
· Pick a material and get the weight from the model volume instantly

■ 2D drawings (Pro)
· Open 2D drawings (DXF) — one finger to pan, two to zoom
· Export a print-ready A4 PDF and share it by message or e-mail

■ Handy extras
· Reopen your 5 most recent files
· Open drawings sent from other apps
· 7 languages: 한국어 · English · 中文 · Español · Tiếng Việt · हिन्दी · नेपाली

■ Private, on-device processing
· Drawing viewing and calculations run on your device; drawings are not uploaded automatically
· Your original files are never modified
· No sign-up, no ads, no internet connection needed to view drawings

■ Free and Pro
· Free: 1 file per day — 3D view, rotate, overall size, edge highlight
· Pro subscription (monthly/yearly): unlimited files + measurement, section, parts, weight, 2D drawings and PDF sharing
· Every Pro feature can be tried 3 times for free before you subscribe
· Subscriptions renew automatically unless cancelled at least 24 hours before the end of the period; manage or cancel anytime in your store account settings

Whenever you need to check a drawing in manufacturing, design, sales or quality, it is ready the moment you install it.
Developed by LIHAON Co., Ltd., an automotive parts manufacturer.

Optional ERP feedback lets existing LIHAON employees verify their employee ID/name and submit request text, comments and app/device details to the company ERP. Drawings are not attached automatically. Reading drawings requires no employee account. Subscription validation/restoration uses the internet.

Privacy: https://erp.lihaon.co.kr/privacy-stpone
EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Recent changes:
Seven languages: Korean, English, Chinese, Spanish, Vietnamese, Hindi and Nepali. Fixed clipped titles on the first screen, overlapping feedback buttons and input-field zoom. Improved translations of features and error messages.