getcover
This is a NDS boxart downloader written in Bash. It depends on Bash, awk, wget and xxd.
It fetches the cover files from GameTDB, and the files are already ready for use with TWiLightMenu++ by RocketRobz.
You can supply games' titleIDs, .nds files or both to it. The script behaves in a case insensitive manner when parsing tIDs. If you supply a valid .nds file, the tID will be obtained automatically.
All boxart will be downloaded to the current directory.
https://github.com/DMSalesman/getcover/releases/latest