I needed in rotation animation for my circle progress bar.
In linux system (openSuse Tumbleweed) all work good.
On smartphone (android 6.0.1) animation stops later than the required (duration value).
And if i start timer with animations, timer inaccurate too.

Example code below.

Rectangle {
	anchors.centerIn: circle;
	rotation: 270;
	transformOrigin: Item.Left;
	Rectangle {
		id: dot;
		width: borderWidth * 3;
		height: borderWidth * 3;
		radius: width / 2;
		x: circle.width / 2 - borderWidth * 2;
		color: progressBorderColor;
	}
}

ParallelAnimation {
	id: animation;
	RotationAnimation {
		target: dot.parent;
		from: 270;
		to: -90;
		duration: loadCircle.duration;
	}
	onStopped: {
		console.log(Qt.formatDateTime(new Date(), "hh:mm:ss:zzz"));
		loadCircle.stopped();
	}
}

console log on android system (duration 20s and 10s):

(onStopped): qml: 21:25:29:969
(onStopped): qml: 21:25:50:394
(onStopped): qml: 21:26:00:642
(onStopped): qml: 21:26:21:145
(onStopped): qml: 21:26:31:391
(onStopped): qml: 21:26:51:875