Open Source Apple iPhone GIS Apps

Mapbox GL JS is a JavaScript library that uses WebGL to render interactive maps from vector tiles and Mapbox styles. It is part of the Mapbox GL ecosystem, which includes Mapbox Mobile, a compatible renderer written in C++ with bindings for desktop and mobile platforms. Mapbox GL JS is part of the cross-platform Mapbox GL ecosystem, which also includes compatible native SDKs for applications on Android, iOS, macOS, Qt, and React Native. Mapbox provides building blocks to add location features like maps, search, and navigation into any experience you create. To get started with GL JS or any of our other building blocks, sign up for a Mapbox account. In addition to GL JS, this repository contains code, issues, and test fixtures that are common to both GL JS and the native SDKs. Mapbox GL JS v2 enables 3D mapping with elevated terrain, customizable skies and atmospheric lighting, a new camera, and performance enhancements.

Lets you monitor your GPS-phone. You have full control of your own data. Both client software (for phones) and server software is free open source, so you might set up your own server or use the default one at opengeotracker.org