Spark is a great email client that heretofore has been free for a long time unless you needed team features. Thew new release is a considerable redesign and, in my opinion, a smart move towards sustainability by requiring a subscription for non-free-tier features. (What some people consider non-free-tier is the subject, as you might imagine, on Twitter, where the usual move-to-subscription mutiny is taking place). Spark is my go-to on iOS and iPadOS, and the dearth of good alternatives on Windows excites me as well. I wrote about it some time back here.

Introducing the all-new Spark, a new approach to productivity and email