VIF — Verify in Field
Android field-verification for architecture & construction plans
Pin a PDF plan to real-world satellite imagery, mark it up on site, and export an annotated record — without leaving the field.
Snap a plan to the real world
Drag three corners of the plan onto live satellite imagery and VIF derives the exact affine transform for the fourth — the plan locks to true GPS coordinates in seconds.
Field-first annotation tools
Numbered count pins, callouts, dimensions, polygons, masks, and revision clouds — built for tapping through a punch list on site, not a desktop mouse.
Annotated PDF, ready to share
One tap turns your markup session into a shareable, annotated PDF record — vector-faithful, with photos and measurements included.
Works where the signal doesn't
Tile-rendered PDF viewer, offline-friendly markup, and a satellite underlay cached locally after first fetch — the file goes where the project goes.
How alignment works
- Open the map — the plan's page opens over live satellite imagery centered on your location.
- Drag three corners onto their real-world position on the imagery.
- The fourth corner locks itself — VIF solves the exact parallelogram so all four corners are mathematically consistent with a single affine transform.
- Commit and the plan is now geo-registered — pins, measurements, and exports are all in real-world coordinates from here on.