RSS Aggregator using wpmu dev plugins and themes

Hello,

I am trying to stay within wpmudev to implement simple rss aggregator. I am looking for simple theme and plugins from wpmu dev - site would be as simple as http://generatorfinansowy.blogspot.com/ - just the list of newest posts across multiple, various blogs.

I have found some solutions e.g. https://www.elegantthemes.com/gallery/aggregate/, http://wpdrudge.com/wordpress-rss-aggregator-theme, but they require subscription to other wordpress provider, and I would like to have everything with you. Publishing needs to be automated (not curated content that requires incoming post acceptance before publishing).

Could you please suggest some possible configurations - theme, plugins of yours?

Thank you in advance,
Milosz