Painting on a phone

How the painting apps that did well on iPhone handle their tools, and what that said about Nijimi's dial. The dial is not what shipped.

The finding

No acclaimed phone painting app makes a radial menu the only way to reach its tools.

Every one that uses a radial either puts it on top of a conventional control, or ships with the same criticism attached: it has to be learned before it helps. Nijimi was the exception when this was written, since the dial was the only control it had.

It is not the exception now. The dial was painted with and dropped, and what shipped is a card of five colours across the bottom of the sheet, swiped for the next card. Both are below: the dial as it stood, and the bar that replaced it.

Where each one puts its controls

Procreate Pocket

iPhone App of the Year, 2018

Sketchbook

Shipping since 2009

Paper by FiftyThree

iPad App of the Year, 2012

Zen Brush 3

The closest peer: East Asian ink

Nijimi, the dial

Built, then dropped

Nijimi, now

Measured, not estimated

Solid blocks are always on screen; dashed shapes appear only when summoned. The four competitors are rough sketches of where each app puts its controls, not measured copies of anyone’s interface. Only Nijimi's are exact.

Side by side

	Main control	The radial	Colour	Brush size	What people say
Procreate Pocket	A toolbar across the top, plus gestures: tap with two fingers to undo, three to redo.	QuickMenu: six tools in a ring. Off by default. It only appears once you assign it to a gesture.	A swatch in the toolbar opens a separate colour panel.	A slider on the side of the canvas.	The benchmark. Its own makers treat the radial as an extra for experienced users, not the main way in.
Sketchbook	The Lagoon: a round puck in the bottom-left corner that opens radial marking menus.	The primary control. Eight tools per menu, and a practised flick picks one without the menu ever appearing.	A colour puck and a separate picker.	A puck you drag to resize, or a slider in the brush panel.	“Brilliant once you understand it, but at first it feels like you’re solving a puzzle just to change brushes.”
Paper by FiftyThree	A tool tray that tucks away when you are not using it.	A radial colour mixer, shown on stage by Apple. The radial people praised was for mixing colour, not for picking tools.	The mixer: drag one colour onto another to blend.	No slider. Width came from how you held the stylus, on its broad edge or its tip.	Praised for how little it asked of you. Acquired by WeTransfer in 2018; now distributed as an Evernote app.
Zen Brush 3	A small, quiet bar. “Simply starting the app means you are immediately ready to draw.”	None.	A short row of inks.	A sizing bar.	Loved for its brush. The complaint that recurs in its reviews: “the brush sizing bar needs some work.”
Nijimi, the dial	A 52pt puck, bottom centre. Nothing else on the paper.	The only control. A half-dial: six pigment wedges × three dilution rings, a four-size rim, and a hub you drag to spin.	Angle picks the pigment; the ring you are in picks the dilution.	The rim: four arcs of 124pt each, the largest targets on the dial.	Built and painted with on the phone, and dropped. What replaced it is below.
Nijimi, now	A card of five colours across the bottom, swiped left and right for the next card, with a slot of clear water beside it.	None. The dial was built, painted with, and dropped: on a phone it took room from the paper, and it had to be learned before it helped.	Tap a swatch. Each card is a few paints, some of them already thinned with water. Choosing a palette has a screen of its own.	A line above the card, dragged left or right, with its stops marked along it.	No reviews yet.

What the research says about radial menus

They test well: People prefer them when asked, and make fewer errors with them than with cascading menus.
Slice count drives errors: The documented failure: more wedges means smaller wedges, and smaller wedges mean wrong picks. This is the one to watch most closely. It is why the dial had six wedges rather than eight, after the inner ring came out at 24pt of arc.
They cost space when open: A large diameter is needed for long labels or many options. Nijimi's dial was 352pt across on a 393pt screen, which was only acceptable because it showed while held and disappeared on release. The card that replaced it is 64pt tall and always there.
They invite clutter: With less room inside a circle, designers tend to cram more into each slice. The rim held four sizes rather than a continuous range, a deliberate refusal of that.

What came of it

The dial went. The research said to keep it, and painting with it said otherwise. On a phone it took room from the paper, and a puck gives no hint of what it does, which is the complaint every radial-first app carries. A radial dial of the whole tin and a single arc of colour both lost to five colours on a card.

Fewer choices in the hand won either way. Slice count was the error driver, and the answer that shipped is the same answer in another shape: five swatches at a time, the rest a swipe away, instead of six wedges and a spin.

Nothing has to be learned first. The weak spot the research named was a control you cannot see. The card is on screen the whole time, and the only instruction the app gives is one line on its start screen.

Size stayed off a tiny slider. Brush size draws complaints even in the best app in this category, and Zen Brush's reviewers single out its sizing bar. Nijimi's size is a line above the colours with its stops marked, dragged with the thumb that is already there.