Free. No ads. Accessible to everyone. Convenient build-in share functionality and a common experience (as you mentioned the common daily word). And of course a

Free. No ads. Accessible to everyone. Convenient build-in share functionality and a common experience (as you mentioned the common daily word). And of course a clean, technically excellent implementation. If it had a single barrier (install an app, create an account, click through ads, etc), it would have been yet another of countless word games. It was a brilliant confluence for a momentary explosion in popularity. All along, though, people were yipping about the grand benevolence and moral supremacy of this version versus clones (when the app itself was, as you mentioned, not that derived from an existing game, even aping the coloring), and that all looks pretty silly now that the creator quite rightly managed a pretty lucrative "exit" for a trivial work. And I applaud them for it, and respect the brilliant choices made to get there.