code: function suggest (opts) {
      opts.strategy = opts.strategy || c.CATEGORY;
      const num = opts.num || 30;
      return resolveApps(opts)
        .then((apps) => getSuggestions(apps, opts.keywords || []))
        .then(R.slice(0, num));
    }
docs: /*
  Suggest keywords based on other apps selected according to a given strategy.