OffTrack

What it is

Import a GPX file — say, a route exported from AllTrails — and OffTrack draws it on an OSM-based map with distance and elevation stats and an elevation profile. It's deliberately view-only: no walk recording, no accounts, no remote database. Trails are just files on the device, a GPX per trail plus a JSON index.

Offline by default

Opening a trail automatically downloads an offline tile pack covering the route's bounding box (padded ~10%, zoom levels 8–15) from OpenFreeMap via MapLibre. Trails with a downloaded pack show an "offline" badge and render fully without a network connection — which is the point, since the best trails rarely come with reception. Failed downloads retry the next time the trail is opened.

GPX files can come in through an import button, Android's share sheet, or "open with" from a file manager — all three converge on the same pipeline: parse, validate, compute stats, copy into app storage.