You can navigate through the sketch in a few different ways: with finger gestures, Navigation Aid (Cube or Onscreen Navigation arrows), and Navigation Hotspots. All four options are explained in this article.
Orbit: Touch the screen with one finger and move around to orbit the sketch.
Move: Touch the screen with two fingers and move them in the same direction to move the sketch
Rotate: Touch the screen with two fingers and rotate the fingers to rotate the sketch
Scale: Touch the screen with two fingers and use the pinch gesture to scale the sketch in or out.
There are two navigation aids available. You can turn them on or off in Preferences.
Navigate using the cube in the bottom right corner of the sketch. If you click and hold the cube you can move it around in space.
You can move the cube to move your view, click on the side of the cube's face to snap to that side, use the arrows to nudge the view in that direction or move the white circle to rotate the sketch.
When this option is turned on the navigation arrows will appear on the screen when holding the Circle button on the side. You can then use the arrows to navigate the sketch.
This option is enabled when both Navigation Aids are turned off.
Tap and hold the Circle button to enable the function. While holding the Circle button tap the screen in the corners of the sketch to snap to different views of the sketch (same as touching the faces of the cube) OR touch the screen and move the fingers around to rotate the sketch.