Thermik

What's inside

3D replay over real terrain

Terrain and aerial photos around your flight, downloaded once, then fully offline. Orbit, zoom, or ride along in chase view and look around while it plays.

Coloured by climb rate

The track shows every thermal and sink at a glance: climb rate, altitude, speed or steepness, with a legend.

Reads your vario

IGC straight from the Skytraxx over USB, plus GPX, KML, KMZ and ZIP. Your files are never changed.

Honest altitude

Barometric shape anchored to GPS, so the pilot is never underground. Choose fused, GPS or baro.

Logbook

Sites, gliders, pilots, notes; search and sort. Launch and landing detected, short recordings tucked away.

Hikes, rides, ski tours, drives, Hike & Fly

Recognised automatically, drawn on the terrain, with their own filter, replay speed and a pin that walks the route.

Share a picture or video

9:16, square or wide; 30, 45 or 60 seconds; Orbit, Chase or Cinematic camera; the stats you choose. Ready for WhatsApp.

Export

GPX with true altitude, KMZ for Google Earth, and the original IGC byte for byte (signature intact).

Backup & restore

One ZIP with logbook, edits, settings and every flight file. New phone in a minute.

Why Thermik?

Built by a pilot who wanted to see last Sunday's thermals again, without an account or a subscription.

Free — no ads, no fees, no sign-up.
Offline — download a flight's area once, replay it anywhere.
Private — no location permission, no analytics; flights never leave your phone.
Open formats — IGC, GPX, KMZ in and out.
Two languages — English · Deutsch.
From the makers of ApexGPS — the free hiking app.

See it in action