From a brief search it seems to me that this has not been posted here before and may be of interest:
https://www.subtask.co/

It is a task manager combining task columns ala Trello, Kanban boards, calendar, timeline and prioritisation matrix. Tasks / subtasks are the main units of information which can be organised in all of the above views.

What I believe sets Subtask apart is its potentally infinite subtask hierarchy potential. Subtasks show their hierarchy information, which is useful to provide context, though taking additional screen real estate.

Subtask has been developed by the same team developing Plectica, mentioned here in the past.

There is currently a promotion for the Subtask personal plan lifetime subscription in Appsumo https://appsumo.com/products/marketplace-subtask/ If you are interested, do check out the Q&A. I understand it allows for infinite boards, and sharing each board with up to 20 people (which need only have the free plan).

Alexander Deliyannis wrote:

From a brief search it seems to me that this has not been posted here
before and may be of interest:
https://www.subtask.co/

It is a task manager combining task columns ala Trello, Kanban boards,
calendar, timeline and prioritisation matrix. Tasks / subtasks are the
main units of information which can be organised in all of the above
views.

What I believe sets Subtask apart is its potentally infinite subtask
hierarchy potential. Subtasks show their hierarchy information, which is
useful to provide context, though taking additional screen real estate.

Subtask has been developed by the same team developing Plectica,
mentioned here in the past.

There is currently a promotion for the Subtask personal plan lifetime
subscription in Appsumo
https://appsumo.com/products/marketplace-subtask/ If you are interested,
do check out the Q&A. I understand it allows for infinite boards, and
sharing each board with up to 20 people (which need only have the free
plan).

Thanks for posting. Does anybody know if there are any reviews other than at AppSumo? I could not find anything when I searched for some type of written or video review.

--Ken

Looks like it's been out maybe a year. Devs wrote about it last September

https://www.linkedin.com/pulse/3-reasons-why-we-built-subtask-christopher-becker

and the only article I found is very basic.

https://venturebeat.com/2020/12/15/subtask-is-a-simple-trello-alternative-for-tracking-and-visualizing-projects/

satis wrote:

Looks like it's been out maybe a year. Devs wrote about it last
September

https://www.linkedin.com/pulse/3-reasons-why-we-built-subtask-christopher-becker

and the only article I found is very basic.

https://venturebeat.com/2020/12/15/subtask-is-a-simple-trello-alternative-for-tracking-and-visualizing-projects/

Appreciate the article links. I played with it under for a few this afternoon. While there are things to like about it, I always seem to have trouble with managers that are heavily based on Kanban Boards as the default or primary view. I do like Kanban boards, but as I am managing a number of projects, this arrangement can get cluttered quite quickly if I want to see all of my projects. This also reminded me a bit of Kanban Tool, which has some interesting features, but I think that I will be sticking with Click-Up for the time being. it seems to offer the best of both worlds - Kanban views and traditional collapsible outline with a folder pane.

--Ken

ClickUp has serious money behind it. I see ads for it on public buses across NYC, something I only previously saw for some Microsoft software. It seems to have nice features, but it also looks like its devs looked at ZenKit 5 years ago and said, "Let's do that". (ZenKit, in the mean time, expanded its feature-set then fractured them into separate a la carte products, including the more consumer-focused To-Do and Hypernotes services.)

satis wrote:

ClickUp has serious money behind it. I see ads for it on public buses
across NYC, something I only previously saw for some Microsoft software.
It seems to have nice features, but it also looks like its devs looked
at ZenKit 5 years ago and said, "Let's do that". (ZenKit, in the mean
time, expanded its feature-set then fractured them into separate a la
carte products, including the more consumer-focused To-Do and Hypernotes
services.)

My understanding is that they do have some serious funding. But I also understand that their CEO thinks very highly of himself, if you know what I mean. But, their customer support is quite fast and responsive, so I will give them that. And I really like how it can be suited to my needs. I have incorporated it into my daily routine at my desktop and find using it to be a plus. The mobile app, however, is not my cup of tea.

--Ken

Ken wrote:

Appreciate the article links. I played with it under for a few this
afternoon. While there are things to like about it, I always seem to
have trouble with managers that are heavily based on Kanban Boards as
the default or primary view.

I was actually drawn to Subtask by its multiple views, including nice Gantt/timeline, as I was to Zenkit (which additionally has mind maps) some time ago. I find this kind of hybrid agile/waterfall approach very useful for large projects--being agile day-to-day without losing the big picture.

I do like Kanban boards, but as I am
managing a number of projects, this arrangement can get cluttered quite
quickly if I want to see all of my projects. This also reminded me a
bit of Kanban Tool, which has some interesting features,

My team worked extensively with Kanban Tool a few years back. It may not have the alternative views of Zenkit and the other hybrids but it is great at scaling. We happily managed hundreds of tasks whereas in some other Kanban boards just a few tens were enough to lose the overview.

but I think
that I will be sticking with Click-Up for the time being. it seems to
offer the best of both worlds - Kanban views and traditional collapsible
outline with a folder pane.

--Ken

FYI I just received an email about a 30%-off coupon for the unlimited Pro plan, using coupon-code FALL30, so a prepaid year costs $42.

But if you're willing to wait until 2 months Black Friday they might repeat last year's 50%-off coupon.

Please note that the lifetime deal mentioned in the original post is still on (for the personal plan)
https://appsumo.com/products/marketplace-subtask/

From their website: "After March 31, 2022, Subtask will be shut down - your task boards will not be available from that date forward."

https://www.subtask.co/shutdown

Sadly, any app can be shutdown at any time. Which remains one of the reasons a subscription service is still riskier than a one-time purchase. And it makes a long track record all the more of a consideration when selecting the apps we use.

Dr Andus wrote:

From their website: "After March 31, 2022, Subtask will be shut down -
your task boards will not be available from that date forward."

https://www.subtask.co/shutdown

Dr Andus wrote:

From their website: "After March 31, 2022, Subtask will be shut down -
your task boards will not be available from that date forward."

https://www.subtask.co/shutdown

Interesting that they placed this announcement on their pricing page rather than their home page. They have made no mention of it on their home page.

--Ken