The DTED Streamer provides an interface for downloading compressed DTED data from a TAK server with GvLF installed.
The server URL can be set within the drop-down by selecting the gear icon and tapping "Set GvLF Server".
The "Check Availability" button scans the current map view for any available DTED data on the server. If data is found, one of the DTED 0, DTED 1, or DTED 2 buttons will light up. Pressing one will begin download of a portion of that DTED tile set. Toggle on "Show Available Tiles" to display available DTED tiles (you may need to zoom out to see them). Toggle on "Show Heatmap" to watch the data download and render in realtime.
When an area of data is finished downloading it is cached, meaning that requesting data from that same general area in the future will only fetch data that is missing (hasn't been downloaded before). You can clear this cache by tapping the gear icon and tapping "Clear Cache". This will allow you to re-download any data that had been cached.