What you need to meditate. (Very little.)
You can start today with a chair and two minutes. Nothing on this page is required. If you do want to buy something, here is what is worth looking for.
Something to sit on
A firm cushion that lifts your hips above your knees makes sitting on the floor far more comfortable. Look for a round cushion (a zafu) filled with buckwheat hulls, which hold their shape, with a zip so you can adjust the filling. A folded blanket does the same job. A chair is also completely fine: sit forward, with both feet flat.
A mat underneath
If you sit cross-legged or kneel, a padded mat (a zabuton) under the cushion protects your knees and ankles. A folded rug or yoga mat works too.
A bell or singing bowl
Optional, and pleasant. A small bowl four to six inches across gives a clear note to open and close a sitting. Listen before you buy if you can, and ignore claims about healing frequencies. The meditation timer on this site has a bell built in.
A notebook
A line or two after sitting helps a practice stick. Any notebook will do. The Thirty-Day Sitting Journal on the shelf is designed for exactly this.
A book to learn from
One good book is worth more than ten apps. Choose an introduction written by an experienced teacher in a tradition that appeals to you, and read it slowly alongside your practice.
What you can skip
Special clothes, incense, apps with streaks, and anything that promises results. The practice is sitting down and paying attention. Everything else is furniture.