Name: WormNav
Rating: 4.7 (46 reviews)
Author: andan

This app allows the navigation in unknown terrain by following a track that is displayed on the Garmin device screen along with a current position cursor (aka worm navigation). 

The navigation track for the Garmin device is managed by the Android companion app and transmitted via bluetooth connection (requires Garmin Connect app).
The navigation itself works autonomously on the Garmin device, i.e. does not require the connection to the smartphone device.

Key features of WormNav ConnectIQ app:
- Show track and current position on Garmin device screen
- Show elevation profile
- Start/stop/save activity
- Configurable auto lap by distance
- Configurable ‘bread crumbs’ (i.e. trace) by distance
- Configurable data screens
- Zoom in/out of map with showing scale
- Show position or track in view center
- North or heads-up map orientation

Key features of WormNav Android companion app:
- Load/store GPX tracks or routes and create local repository on Smartphone
- Show GPX tracks or routes in Open Street map
- Transmit track/route to connected Garmin device via blueooth
- Optimize track/route (reduce number of way/track points)

Please visit https://andan67.github.io/wormnav/ for a comprehensive user guide and important notes.

The ConnectIQ and Android companion apps are free and open source software (see https://github.com/andan67/wormnav).
Feel free to modify the code for your needs or to contribute additional features or improvements.