IONIC2 - app gets killed after some time even when using Background Geolocation - ios

Question

I have an IONIC2 app, which needs to wake up every morning at 8 AM for 20 minutes to send user reminders based on the user's geolocation.
I am using this plugin (which uses IOS significant changes API to monitor changes in user's location)
https://github.com/mauron85/cordova-plugin-background-geolocation
The problem:
The app doesn't get killed when I close the app and the background geolocation works for me fine for some time. I have tested upto an hour. But when I wake up next morning, I find the app was killed by IOS.
I know there is another plugin to keep the app running in the background https://github.com/katzer/cordova-plugin-background-mode, but I have read tons of complaints from people that it will cause your app to be rejected by the AppStore (In fact, the plugin has a disclaimer to the same effect too).
For waking up the app tomorrow, I simply set a setTimeout
setTimeout(function(){
console.log('waking up');
self.helper.scheduleLocalNotification('Hello World', 'Good Morning', 10, "");
self.ionViewDidEnter();
}, wakeupinMilliSeconds);
Here is my geolocation code:
setupBackGroundGeolocation(){
let config = {
desiredAccuracy: 100,
stationaryRadius: 50,
distanceFilter: 100,
interval: 5000,
pauseLocationUpdates: false,
debug: false, // enable this hear sounds for background-geolocation life-cycle.
stopOnTerminate: false, // enable this to clear background location settings when the app terminates
};
BackgroundGeolocation.configure((location) => {
console.log('[js] BackgroundGeolocation callback: ' + location.latitude + ',' + location.longitude);
this.currentLocation.lat = location.latitude;
this.currentLocation.lng = location.longitude;
Promise.all([
//I do some calculations here.
]).then(d => {
// IMPORTANT: You must execute the finish method here to inform the native plugin that you're finished,
// and the background-task may be completed. You must do this regardless if your HTTP request is successful or not.
// IF YOU DON'T, ios will CRASH YOUR APP for spending too much time in the background.
BackgroundGeolocation.finish(); // FOR IOS ONLY
});
}, (error) => {
console.log('BackgroundGeolocation error');
}, config);
// Turn ON the background-geolocation system. The user will be tracked whenever they suspend the app.
BackgroundGeolocation.start();
}

Answer 1

I don't use this plugin but had same symptons. I couldn't figure out what was wrong: no error messages, no clues but app kept closing after a few hours.
I guess there was something messed up after installing and uninstalling so many cordova plugins. Now the app is much more stable. I removed and added platform. That seemed to do the job.

Answer 2

I've been reading about ionic2 and performance. Among so many reasons, a possibility about low performance and crash is related not to unsubscribe from observables. Read about async pipe and .unsubscribe observables when component is destroyed ngOnDestroy
Another problem i found was a very basic mistake developing in angular. I loaded everything in the app module so this required lot of memory to load the entire app at once. I guess with slow terminals that can affect more. Anyway, basic angular concepts as .module files should be understood.