As a touch-based app on iOS, Concepts generally sticks to the standard iOS gestures: one and two finger taps, tap+holds (long-presses), and drags. You can also set three and four-finger taps. You can customize all of your gestures how you like them in the Settings menu. Just tap Settings -> Gestures, scroll through the options and pick what you'd like.

These are the basic gestures you can expect when working in the app:

View Only Mode (no active tool):
  • One finger drags the screen.
  • Two fingers zoom and rotate.
Freehand Mode (with an active tool):
  • One finger or stylus draws.
  • Two fingers rotate and scale the infinite canvas.
  • Tap a menu button (Layers, Precision, Import, Export) to open it.
  • Tap+hold any menu, or tap+hold the outer ring of the tool wheel, to select the menu and move it about your workspace.
  • Tap+hold on the canvas with one finger to activate Selection Mode.
  • Double-tap any eraser (Slice or Mask) on your tool wheel to quick-clear your canvas.
  • Tap the active tool to bring up the Brushes menu.
  • Tap+hold the color circle at the center of the tool wheel to bring up the Colors menu (where you can customize colors and palettes).
  • Double-tap the Import button (when not open / active) to immediately bring up the Import menu.
Selection Mode (using either the Selection tool or via tap+hold on the canvas):
  • Tap the toggle on the selection popup at the bottom of the screen to choose between Lasso, Item Picker and Color Picker (tap+hold shortcut gesture only, not the arrow tool).
  • A tap+hold+drag with Item Picker or Color Picker active will drag the picker about.
  • With Item Picker, tap again with an additional finger to add / subtract items from your selection.
  • A tap+hold+drag with Lasso active will allow you to select multiple things at once.
  • Tap anywhere on canvas to exit the selection.
  • Once selected, one finger drags the object.
  • Once selected, two fingers scale and rotate the object.
  • Once selected, tap a control point or two (the dots at the corners of your selection) to activate them, then use one or two fingers to drag, pinch or expand the relevant corners of your selection.
Precision Mode (with the Precision menu open):
  • One finger or stylus draws. If you have a Shape Guide active on screen (like the Arc tool), you can also drag the shape without changing the shape properties using one finger on the crosshairs (center) of the tool, or further still, you can move one "handle" at a time with one finger. (It's easier than it sounds.)
  • Two fingers rotate and scale the canvas, unless you have a Shape Guide on screen, in which case it will rotate and scale the guide. Using two fingers on the Shape Guide handles will bend or straighten or elongate the guide.
  • Double-tap on the crosshairs of an active shape guide for one of the following actions: straight line toggles between infinite and limited to handles; angle snaps to a right angle, arc snaps to a half circle; ellipse snaps to a circle; and rectangle snaps to a square.
Measurements:
  • Tap+hold any measurement to edit that measurement. Some measurements may be editable from the status bar at the top of the screen.
  • A quick tap on a measurement will solidify it to the canvas. To remove it, select it or the stroke it's attached to, then tap the measurement again so the two dots surrounding it reappear.
  • To move a measurement, make sure it’s selected (or the stroke it's attached to), then drag it with one finger.
Two Finger Tap can be configured in Settings -> Gestures to one of the following options:
  • Undo (default)
  • Redo
  • Select Last Item
  • Show Layers
  • Show Color Wheel
  • Tool Setup
  • Show Objects
  • Toggle Shape Guide
  • Toggle Interface
Three Finger Tap can be configured in Settings -> Gestures to one of the following options:
  • Undo
  • Redo (default)
  • Select Last Item
  • Show Layers
  • Show Color Wheel
  • Tool Setup
  • Show Objects
  • Toggle Shape Guide
  • Toggle Interface
Four Finger Tap can be configured in Settings -> Gestures to one of the following options:
  • Undo
  • Redo
  • Select Last Item
  • Show Layers
  • Show Color Wheel
  • Tool Setup
  • Show Objects
  • Toggle Shape Guide
  • Toggle Interface
  • Toggle Canvas Rotation
  • Toggle Canvas Zoom
  • Do Nothing
We cover a lot more ground in the Manual. Alternatively, you can read an illustrated version complete with gifs on Medium (created for Concepts 4, but the gestures are the same). You’ll get the hang of them very quickly!