How to Launch an App in Foreground When I Enter an Ibeacon Range

Can I launch an app in Foreground when I enter an iBeacon range?

No, I do not believe this is possible. Apple's philosophy is that the user is in control of what app is in the foreground. The only three ways to bring an app into the foreground are: (1) tapping its icon, (2) tapping a notification associated with the app or (3) through a custom URL to launch the app from a different app.

I have a colleague who has long insisted this is possible, so I tried it myself today to see for sure. In our open source SavengerHunt app, I modified the AppDelegate's didDetermineState method to add the code below to try and force the app into the foreground.

        NSLog(@"Attempting for force window %@ into foreground", self.window);
        [self.window makeKeyAndVisible];
        NSLog(@"Done with attempt");

The code executed when an iBeacon was detected in the background, and the log lines showed up as expected. The app, however, did not change to the foreground.

       2014-03-06 11:35:43.655 scavengerhunt[277:60b] Sending a notification that a beacon is nearby
       2014-03-06 11:35:43.678 scavengerhunt[277:60b] Attempting for force window <UIWindow: 0x14e96730; frame = (0 0; 320 480); gestureRecognizers = <NSArray: 0x14e95870>; layer = <UIWindowLayer: 0x14e961f0>> into foreground
       2014-03-06 11:35:43.686 scavengerhunt[277:60b] Done with attempt

Given that this doesn't work, your best bet is to present a local notification to the user. If they tap on it, your app will move to the foreground.

Can iOS still launch an app in range of iBeacon in iOS 10?

Getting an app to auto-launch from a not-running state based on iBeacon detection is surprisingly easy with CoreLocation and iBeacon.

In order for it to work a few pre-requisites must be met:

1. The app must have been manually launched once before.
2. The app must request and obtain "Always" location access from the user on first launch.
3. The app must register a CLBeaconRegion with CLLocationManager by calling locationManager.startMonitoring(region: region), and set the locationManager.delegate. Since you also want to range, you can simultaneously call startRanging(beacons: beacons, region: region). It is usually easiest to do this in your AppDelegate.
4. The phone must have location enabled and bluetooth turned on.

If you do all of the above correctly, then iOS CoreLocation will remember that your app has registered the CLBeaconRegion and auto launch your app on beacon detection. Even if you reboot the phone, or kill your app from the task switcher it will do this. After auto launching your app into the background, it will call the didEnter(region: region) callback on your delegate and then start calling the didRange(beacons: beacons, region: region) callback once per second for about 10 seconds, until the operating system will once again suspend your app.

There are lots of ways to make mistakes when testing so this doesn't work. But if you do everything right, this is pretty darn reliable.

What you can't do is bring the app to the foreground programmatically, because iOS does not allow this. On iOS, a user must gesture to bring an app to the foreground -- this is nothing to do with beacons, but a long-standing rule in the design of the OS. This is why many apps send a local notification while they are in this brief background state after detecting a beacon to give the user a way to bring the app to the foreground.

Starting the App when an iBeacon is detected

You probably need to clarify what you mean by "the app is not running". Do you mean:

1. The app has been installed but never launched
2. The app has been launched once but since rebooted
3. The app has been killed from the task switcher

Using the code above, here is the expected behavior in each case:

1. The app will not be running and cannot auto-launch the Activity.
2. The app will start scanning for beacons periodically after boot and will launch the Activity when one is detected.
3. The app will not be running and cannot auto-launch until charger connect/disconnect or reboot. After that time, behavior is as in (2). More details on this case are available here.

It is important to note that when no Activity is visible, the library will only do a scan tyo look for beacons every 5 minutes, so detection can take that long. This interval is fully configurable.

The restrictions on case (3) are imposed by Android OS. An event must occur allowing restart of an app after it is killed by a user.

How to make iBeacon foreground ranging for CLProximityImmediate faster in iOS?

The delays you mention are likely caused by four factors:

1. The time it takes for CoreLocation to give you a single ranging update: 1second
2. The time it takes for CoreLocation's rolling average estimate of "accuracy" (distance) to settle out on the value for a new location from an old location. My experiments show this is about 20 seconds.
3. The time it takes to get an immediate reading given radio fluctuation this should be 2-3 seconds at most.
4. The calibration constant of your beacon. If your beacon is not calibrated properly, CoreLocation may overestimate the distance, causing (3) to take much longer until random variation happens to give you an immediate reading.

To speed up the above, first ensure proper calibration. Next, you may want to abandon iOS' distance estimation in favor of your own, based on the RSSI reading you get with each ranging callback. The advantage is you can get rid of the 20 second lag caused by the rolling average. But the real tradeoff is that you will see much higher variability on your distance estimate. Leading to false positives when you are further away than you want .

IOS7 iBeacon: How to launch app when detect a beacon(app not running)

You cannot launch the app UI when a beacon is detected because of iOS restrictions. The closest you can do is to send a local notification on beacon detection, giving the user a message and allowing the user to choose to launch the app UI by tapping on this notification.

See here for a more detailed explanation:
Can I launch an app in Foreground when I enter an iBeacon range?

How to start GPS tracking triggered by a iBeacon in Xamarin iOS?

We actually recently wanted to implement this behavior in one of our apps too, and found that if we start significant location updates (startMonitoringSignificantLocationChanges) in the foreground, then we're able to start regular location updates (startUpdatingLocation) in the background, in our didEnterRegion implementation.

(Naturally, your app needs the "always" authorization to access Location Services, and the "Location updates" Background Mode enabled.)

Our app is still pending review, so whether that's a bug or a feature of Core Location, and whether Apple is okay with that, remains to be seen.

beacon detecting in foreground, background and kill (remove from background) app

You must add and allow location in NSLocationAlwaysUsageDescription.If you are in beacon region that time didEnterRegion method execute and out of beacon region that time didExitRegion method executed, that time we start and stop device discovery. we can able to detect beacon in foreground , background , lock phone and in kill state of application.

Modify your method as given below.

    func locationManager(_ manager: CLLocationManager, didEnterRegion region: CLRegion) {
            print("Region Entered")
            devicesManager.startDevicesDiscovery()

        }

        func locationManager(_ manager: CLLocationManager, didExitRegion region: CLRegion) {
            print("Region exited")
            devicesManager.stopDevicesDiscovery()    
        }

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