Contact person: Business Client

Phone:Show

Email:Show

Location: Mount Prospect, United States

Budget: Recommended by industry experts

Time to start: As soon as possible

Project description:
"I need a cross-platform solution that recreates the core idea behind the Android-only “Custom Maps” app: placing my own map image on top of a live GPS base map and seeing my position update in real time. The end result should run smoothly on both iPhone and Android and also install as a PWA for users who prefer the browser route.

Core workflow
• Import a custom map through a simple file-selection dialog (no drag-and-drop required). Both JPG and PNG images must load without issues.
• Let me pin at least two, ideally four, control points on the image and match them to real-world GPS coordinates so the overlay calibrates correctly.
• Render the calibrated overlay above an interactive base map—OpenStreetMap presented with Leaflet (or another comparable slippy-map stack) is fine. Users must be able to adjust overlay transparency on the fly.
• Continuously display the device’s GPS location on that custom layer and allow normal touch gestures for pan and zoom.
• Allow multiple projects, saved locally on the device for quick reopening, and make every project available offline once downloaded.
• Provide a straightforward way to export or share a finished map package so another app user can import it and see the same overlay on their own phone.

Nice-to-haves
If you can wrap the PWA with Capacitor or a similar tool so it’s publish-ready for the App Store and Google Play, that would be ideal—but the primary requirement is a fully working PWA that meets the bullet points above.

Acceptance
1. Load a 5 MB PNG via file picker, calibrate four points, and see the overlay line up within ±10 m on a hiking trail.
2. Toggle transparency from 0 % to 100 % with no more than a 200 ms frame delay on mid-range devices.
3. Switch to airplane mode after downloading; the base tiles and custom map still render, and GPS tracking continues.
4. Export the map, import it on a second device, and obtain an identical result without manual tweaks.

Code ownership transfers to me, and I’d like clear instructions for building and deploying the app plus a quick demo video that proves the four acceptance steps." (client-provided description)