Point. Know. Build.

We're developing an app that measures the width, height, diagonal, volume and level of things you can see – a TV, a table, a hole, a window, a door, a structural opening or a gap – using your phone's on-device camera, AR/LiDAR geometry and motion sensors. It includes 4 user-tapped modes — Width, Height, Diagonal (with live frame-squareness check in mm) and 4-tap Cubed volume (m³, litres and ft³) — each displayed with an indicative ± mm uncertainty range, plus the Pro Spirit Level, which uses your phone’s motion sensors to show tilt in degrees and slope in mm per metre. You tap each measuring point on screen and your phone calculates the size with an indicative ± mm uncertainty range; the app does not guess or auto-fill sizes by itself. Once you have tapped the points, Ask Ai can then provide practical installation advice and (on Pro) a tailored Materials & Fixings Offer based on your captured measurements and job photo.

No. You move the phone slowly over the surface until it's ready, then aim the dot at the first point and tap, move across to the other point and tap. The app works out the distance between your taps.

Yes. Tap the first point, move across and tap the other for the width. Then tap the top, then the bottom for the height, or skip the height if you only need the width. Depth is optional. For Diagonal, tap two opposite corners (or measure Width + Height) to get √(W²+H²) plus a live Squareness / Out-of-Square check in mm. For Cubed, tap one shared corner and the ends of length, height and depth (4 taps) to get volume in m³, litres and ft³. With Gapeye Pro, the Spirit Level uses your phone’s motion sensors to show tilt in degrees and slope in mm per metre, with a bubble, a level indicator, a calibrate/zero button and horizontal and vertical modes; Basic users see it locked with an Upgrade to Pro prompt.

Sometimes it may suggest edges and show “Edges found – tap to accept”. It's only a helper: it never fills in a size by itself, and you decide by tapping.

Tap Undo to remove the last point, or Start again to begin a new measurement.

No. Gapeye measures with your phone's camera and AR. For very tight spots, you can optionally lay a bank card on the same surface for extra help.

Once you have tapped your measurement points on screen, Ask Ai sends the captured dimensions, the ± mm range, and (if attached) your site photo and note to provide practical fitting advice, clearance checks, and (on Pro) a tailored Materials & Fixings Offer with trade retailer links. The measurement itself is always calculated on your phone from your tapped points using AR/LiDAR and motion sensors — never guessed by the AI. Basic includes 5 free Ai answers after sign-up; Pro includes unlimited Ask Ai on our smarter model.

Gapeye supports millimetres (the default), centimetres, metres, and feet/inches down to 1/16 in, plus cubic metres (m³), litres, and cubic feet (ft³) for 4-tap Cubed volume, and degrees (°) plus slope in mm per metre for the Pro Spirit Level.

Gapeye v1.0 is built for ARKit-compatible iPhones and iPads (with automatic hardware LiDAR depth on iPhone Pro / iPad Pro models and multi-ray visual AR plane detection on non-LiDAR models) and ARCore-compatible Android phones, using the phone's motion sensors (gyroscope and accelerometer) for the Pro Spirit Level and an optional ISO/IEC 7810 ID-1 bank/ID card reference mode for close-range planar checks (<50 cm). While formal multi-handset benchmark testing is being completed across devices, the final tested handset matrix will be published alongside launch.

Published peer-reviewed literature benchmarks for smartphone LiDAR and ARKit/ARCore raycasting report typical target design envelopes of ±15 mm on tracked planes and ±25 mm on feature points (aligned with RICS Measured Surveys Band D/E ±10–25 mm workflow context), and ±4 mm for close-range coplanar ISO/IEC 7810 card homography. Gapeye's own formal multi-handset benchmark testing is currently ongoing prior to release; every on-screen reading is an indicative site estimate displayed with a live ± mm uncertainty interval (JCGM GUM) and must always be verified with a physical tape measure or certified spirit level before cutting, drilling, ordering, or structural work.

In target design models, close-range coplanar checks under 50 cm can use a standard bank or ID card (ISO/IEC 7810 ID-1, 85.60 × 53.98 mm) placed on the same surface as a 4-point scale reference (±4 mm target design estimate in published planar homography literature). Gapeye's formal minimum-gap and across-device validation is being completed prior to release, and every reading shows its live ± mm uncertainty range so you can confirm tight tolerances with a physical rule or tape.

Core measuring works offline on site with no signal: point-to-point AR/LiDAR measuring (Width, Height, Diagonal, and 4-tap Cubed volume), the Pro Spirit Level (tilt in degrees and slope in mm per metre from your phone’s motion sensors), saving measurements and photos locally on your phone in Measure & Save, and exporting A4 PDF & CSV Job Sheets locally all work without internet. An internet connection is required for Ask Ai (cloud AI trade advice and the Pro Materials & Fixings Offer with retailer links), account sign-in and cross-device cloud sync, subscription purchase/restore verification, and loading sponsored ads on the Free Basic plan.

Gapeye is available now on Google Play (Android) in many countries; the iOS App Store version is coming soon (in Apple review). Availability can vary by country and device.

Available now on Google Play (Android); iOS App Store coming soon (in Apple review). Use the Google Play button on this page to install it on Android; the App Store button will be activated once Apple approves the iOS version. You get 2 free measurements before creating an account, unlimited measuring on the free ad-supported Basic plan, or Gapeye Pro (3.99 a year).

Basic is free with ads. Pro is 3.99 a year and removes ads and adds smarter Ai, PDF export and Measure & save.

Yes. Basic is ad-supported and Ask Ai recommends regional trade materials at the exact moment a professional measures an opening. Merchants and brands can sponsor Basic in-app banners, Ask Ai trade partner links, or banner slots on gapeye.com — contact info@gapeye.com.