22I want to manage my needles and hooks

Go to Tools → Needles & Hooks. Everything you knit and crochet with lives here, in one list: circulars, straights, double-points, interchangeables and hooks, each with its size and length. The tabs across the top are My Tools, Info, and then quick views for Standard, Tiny and Hooks.

You do not have to import anything. If you keep needles on Ravelry they appear in this list from the start, badged Ravelry. Anything you add in the app is badged Stash2Go, and the two sit together in one collection - which is the point, because when you are standing in a yarn shop you do not care which system a needle was typed into.

The Info tab counts everything up: how many circulars, straights, double-points and hooks you own, the range of sizes you have, and then a breakdown of which sizes and lengths, in which quantities. This is the tab that answers "do I own three 4 mm circulars or did I only think I did".

The + button adds anything that is not on Ravelry. Pick the Category (needles or hooks), the Type (straight, circular, double-pointed or interchangeable), then the Size and Length from the chips - metric and US shown together, so you do not have to convert in your head. More details opens brand, material and a note.

Two things live in the header. The Size Converter takes one size and gives you the others: choose knitting needle or crochet hook, choose metric, US or UK, type the size. The Conversion Chart shows the whole table at once - US, metric and UK in three columns - which is what you want when a pattern is written in a system you do not think in.

Tap a tool and you get its details and its state - Available, In Use or Loaned. Assign to Project ties it to what is on it, and the list then shows it as in use with the project named. Release from Project frees it again, and finishing a project releases its needles for you, so the list does not slowly fill up with needles that are only theoretically busy.

Lend Tool records who has your 4 mm circular. Type a name, or search for their Ravelry profile so the name is more than a name. The tool shows as Loaned in your list until you tap Mark Returned.

The filter beside the search box narrows the list to All, Needles, Hooks, Available, In Use or Loaned; sort arranges it by Type, Size, Brand or Recent; and the search box matches on name. Standing in a yarn shop wondering whether you already own a 4.5 mm - Available answers it in one tap.