.tar, .tar.gz, .zip or any other might be not so obvious.
When I used Debian based Linux distributions, mostly I've installed external software in /opt directory and there are few reasons to do it here:
/opt stands for "optional add-on software packages", so basically anything that is not part of system/opt directory where are usually stored external apps.png or xpa) and save in /usr/share/pixmaps/ directory to with chmod 644.
sqlitestudio.desktop into /usr/share/application and paste below entry:
[Desktop Entry]
Name=SqliteStudio
Comment=SQLite editor
Exec=/opt/SQLiteStudio/sqlitestudio
Icon=/usr/share/pixmaps/sqlite.png
Terminal=false
Type=Application
Encoding=UTF-8
Categories=Network;Application;
Path=