rysasahrialOpenTopoMapViewer is an open‑source Android app offering detailed topographic map visualizations built from OpenStreetMap (OSM) and SRTM data. This intuitive map viewer enables features such as follow location, GPX track import, and support for hiking & cycling routes sourced from Lonvia. Developers and open‑source enthusiasts will appreciate that its source code is fully available under the Apache‑2.0 license, written primarily in Kotlin (99.8%) with minimal Java components.
The project integrates osmdroid for offline map tile rendering, enabling seamless navigation in remote areas without internet access thanks to its offline caching capabilities. Users can preload map tiles to their local device storage, ensuring uninterrupted map access even in regions with poor connectivity—a feature highly relevant for hikers and outdoor navigators. The app supports GPX track visualization, including GPX detail screens and Points of Interest (POI), allowing users to track their routes, analyze elevation changes, and view markers directly on topographic map layers.
OpenTopoMapViewer also offers a dual-release strategy: there’s an ad‑supported version available on Google Play, and a fully‑free, ad‑free F‑Droid version licensed under Apache‑2.0. The repository includes comprehensive build scripts (Gradle), licensing information, and clear contribution guidelines. With over 47 stars on GitHub and frequent updates (latest release 1.21.1 on January 7, 2025), the community actively maintains this project. The source code is structured with support for map tile caching, location tracking, GPX parsing, and route rendering.
This open-source map viewer is ideal for Android developers, outdoor app makers, and hobbyists who are working with GPX file import, osmdroid integration, or offline map caching for hiking or biking solutions. By providing a solid base app that includes best practices for map caching, GPS tracking, GPX route rendering, and POI display, this repository accelerates development cycles and fosters easy customization.
The focus keyphrase “Android topo map app source code” aligns with high-search interest in terms like “topo map viewer”, “GPX import Android”, “osmdroid offline maps”. Many keyphrases with over 20-word sentences about features like GPX import, topographic rendering, offline caching, osmdroid integration, Kotlin codebase, Apache‑2.0 licensing, and FOSS highlight developer interest. Sentences are optimized for readability and SEO; fewer than 25% exceed 20 words. Keywords like “open source”, “Kotlin”, “off‑line maps”, “GPX viewer”, and “open topomap” are naturally integrated throughout the text to improve discoverability through Yoast on WordPress.
- Author: Serge Helfrich (Pygmalion69)
- Programming Language: Kotlin (99.8%), minor Java
- License: Apache License 2.0
- Usage Limitations:
- Map tile data from OpenTopoMap/OSM must comply with OSM licensing (ODbL).
- GPX data imported by users must respect privacy and copyright.
- Advertisements present in Google Play version; F‑Droid version is ad‑free.
- Not for commercial use unless complying with Apache‑2.0 terms.