Things and Rymi disagree about what a task app is for. Things is a place to keep everything: a calm, beautifully organised home for every project, every someday-maybe, every task you might one day get to. Rymi is a daily commitment to the few things you will actually do today.
That is the whole difference, and every other one follows from it. Things will happily hold a thousand tasks in tidy projects and never once ask you to choose between them. Rymi's entire interaction is the choosing. So the real question is not which app is better made - Things is superb - but which bet matches how you want to work: a permanent place for everything, or a short list you commit to each morning.
Things is the best-designed task app on Apple platforms, and it earns the devotion it gets. Areas, projects, headings, tags, deadlines, a quiet gesture-driven interface, and Things Cloud sync that simply works - it holds a large, structured system without ever feeling heavy. Few apps in any category are this considered.
It is also a one-time purchase, not a subscription: around $50 on Mac, with the iPhone and iPad apps sold separately, and sync included at no extra cost. For people tired of renting their software, that model is a genuine feature, not a catch. If what you want is a beautiful, permanent home for everything you might do, nothing beats Things, and Rymi does not try to.
Rymi starts from the other end. Today is not a container you fill - it is a commitment you make each morning and hold through the day. There are no areas to file into, no projects to maintain, no archive to tend. You capture freely, decide what actually matters today, and the app holds you to that short list instead of to an ever-growing one. It is free, native to Mac and iPhone, keyboard-first - every action has a shortcut - and it needs no account to start.
Here is what Rymi gives up, plainly. If you want deep project structure, areas, tags, and a permanent organised archive of everything you have ever planned, Things does all of that and Rymi deliberately does not. Rymi is also younger and less feature-rich. Those are real trade-offs, chosen on purpose - but they are trade-offs, and you should weigh them before you switch.