code: function getPackages(app, cb = null) {
    let stdout = '';
    const ls = spawn('npm', ['ls', '--json', '--prod', '--depth=0', '--long']);
    ls.stdout.on('data', data => {
      stdout += data;
    });
    ls.stderr.on('data', data => {
      app.error(`stderr: ${data}`);
    });
    ls.on('close', (code) => {
      if (0 !== code) app.error('child process exited with code %s', code);
      app.debug('loading installed zealder packages');
      var p = JSON.parse(stdout);
      if (p.dependencies) {
        // now set packages to state
        setPackagesState(app, p.dependencies, cb);
      }
    });
  }
docs: get all installed zealder apps/themes