Is there a way to have this module's functionality in Drupal 8?

There's Views Aggregator Plus, but I couldn't get the summary row to show up.

Having a dedicated module for this makes sense. Let's see if anyone's interested in porting this one.

For my use case, I needed to sum the values in a column, which I resolved by creating another aggregate view, and placing it in the footer with Global: View area.

I realize this issue is more than a year old and may no longer apply, but I have created a Drupal 8/9 compatible release that can be found on this project's home page and here: https://www.drupal.org/project/views_summarize/releases?version=1

I'm closing this as fixed. If you have any follow up issues, please create a new ticket.

Shoot! I accidentally overwrote the .module file with the .info.yml file with some copy operation, and deleted all my working copies, so I now need to recreate the .module file.

1.1.0-beta2 is now up and ready for download. AND, has the correct .module file.

Very cool. Thanks for your work @oadaeh. Does it include the overhaul patch (that allows changing the currency, the decimal point, etc)? https://www.drupal.org/project/views_summarize/issues/1876548#comment-12...

I'm surprised you were able to start a new 1.x branch as that was used in D7 (7.x-1.x); normally it would be a version upgrade to 2.x, but it seems like this is working. You could, however, bump it to 2.x for the next one if you wanted (to avoid the confusion).

I'm sorry for the long delay in getting back to this. I had meant to reply a few weeks ago, but I've been busy with other things, most specifically, paying my bills.

@NWOM: As I wrote in the release notes, "This is just a straight port of the 7.x-1.1.x code with no modifications other than making work in Drupal 8." So, no, I did not include that or any other modification.
However, I did take a look at that issue, the patch, and the comments, and I think it would be good to include, so I'm going to add it to the 7.x branch first, then update the 1.x branch.

@colan: I'm not sure I understand you. The branches are just Git branches and they are not the same name, i.e., the 7.x-1.x Git branch name is not the same as the 1.1.x Git branch name, so there was no problem adding it.
Also, since at least D5, it has always been my impression (based on documentation I have read and conversations I have had or heard in the past) that the part of the version after the hyphen was not supposed to be dependent on the Drupal version. That's what the part before the hyphen is for. While these pages don't explicitly state it, it is implied based on the wording:
* Drupal 7 Version numbers
* What do version numbers mean on contributed modules and themes?
Functionally, the 1.1.x branch is the same as the 7.x-1.x branch. The only differences are the parts that make the functionality work with the specific version of Drupal, so the 1.x part remains the same. However, I think using a semantic versioning model going forward (that does not include the Drupal version) will change how that works. I did spend quite a bit of time attempting to find something that stated how the versioning was supposed to be going forward, and while I could not any canonical document more clear than Semantic versioning model, based on what I was able to find, I think I have it right.

My current plan is to create a 7.x-2.x branch for the changes in that other issue mentioned above and incorporate them into a 1.2.x version for the D8 version. I'm creating those additional branches branches because the functionality is different enough and requires an update (that has not yet been written), so I don't want people just blindly updating without realizing what's at stake. After that, I'm going to create a 2.0.x branch that modifies how the module performs its functionality to be more D8 integrated (using plugins for the various summaries, and maybe modifying how the summaries are rendered). I've actually already done the plugin work for 2.0.x, so I just need to get the other things done. :)