A couple months ago I posted a question about Blynk failing to reconnect to BLE after a disconnect from my iPhone. There was acknowledgement of the issue, but no resolution. More recently, I looked for the GPS trigger widget, only to find that it didn’t exist in the iOS version of Blynk.
Is this just an oversight? Low priority? Is Apple not allowing sufficient access to those features?
Don’t forget to search…
Yep, I did see that thread; but since it hadn’t been addressed in a year and a half, I thought I’d give a little nudge. 
I use IFTTT’s GPS trigger on a couple of my Blynk projects, but think that removing the middle man would improve reliability, and proper BLE connection would allow me to geofence from a much more precise range. Both of these limitations seem specific to the iOS version of Blynk.
It’s not on iOS because widget is not very used overall and we lowered its priority.
I recently resurrected an old iPhone 4s for my IoT experimenting, so just learning what works/dosn’t on the iOS side. I see that the iOS map jumps to & follows new pin drops… not sure if that would be useful with geofencing, but it is NOT available on Android… so win some loose some, depending on platform I guess.
The GPS streaming widget does work on iOS… so at least providing the device’s coordinate data. Can you not make up your own limited triggering with code in the sketch?
Gunner, with multiple people in the household, I wonder what is the best way to implement Geofence to trigger when ALL smart phones are away (Blynk shared app user e.g. my wife. cannot enable GPS stream). I have an alarm system and would like it to turn on automatically when no body is at home. I saw some people mention BLE, and not sure if it is good. Thanks a lot!
I am not a developer, so no idea on the GPS trigger options for iOS… but I have seen some recent videos about longer range RFID tags and how they can be attached to things (phone, phone case, forehead 
) for zone location detection. No, not a Blynk specific thing, but perhaps another integration option to a IoT setup.
Hopefully more people use IOS widgets so we can bump up the priority in the future. I can geofencing is nice for home automations such as:
Why not?
Assume I use the following code to stream the GPS location, I can get the location of my phone and set a geofence trigger for this iPhone base on its coordinate. Is there a way to track the 2nd iphone?
BLYNK_WRITE(V1) {
GpsParam gps(param);
// Print 6 decimal places for Lat, Lon
Serial.print("Lat: ");
Serial.println(gps.getLat(), 7);
Serial.print("Lon: ");
Serial.println(gps.getLon(), 7);
// Print 2 decimal places for Alt, Speed
Serial.print("Altitute: ");
Serial.println(gps.getAltitude(), 2);
Serial.print("Speed: ");
Serial.println(gps.getSpeed(), 2);
Serial.println();
}
Yes, if you share your project, the BLYNK_WRITE(V1) will be triggered with location updates from both phones. The issue is that at the moment there is no reliable way to distinguish which phone sent the location, though it may be enough for a backup system that signals if everyone has left a home with alarm system turned off.
p.s., looks like a simple and effective improvement would be adding the fifth parameter along with lat lon etc, sort of a sender identifier. I’ll include this in upcoming iOS Blynk app update.
Good idea, I didn’t know that V1 (i.e Location) can be coming from more than one phone! Having the identifier will even make it more clear. Thanks Eugene.
A question on GPS stream units, what is the number I set if I need the GPS location to be triggered (compare coordinates in code) when the phone is 100 meters away? (I.e. how does the number be converted to a distance) Thanks
Sounds like a job for Google 
@Eugene: Would be good to have an identifier for all sensors (not just GPS) to distinguish which phone has sent the value.
Great idea… I recall it being mentioned in the forum a few times, but still couldn’t find it on the roadmap… so I just added my own request. Keep a look out for it and vote
+1
Like @chrome1000, I’m currently using IFTTT to trigger a « geofenced VitualPin » for my alarm. It works great but needs an IFTTT account on each iPhone. Would like to see this feature integrated in Blynk !