How can I know my app was previously installed on a phone?

Question

I am trying to make an app which allows only single account per device. Now what I am trying to know is a property of a phone which never changes. At first I thought I could save MAC address of a device in my database but I read in one of the question on SO that know in android when we try to access MAC address programatically we get a constant that is same for every device. I would like to know what never changing property of an android device can I access programatically.

Also in future I would like to develop that app for iOS, is there same non changing property of iOS phone that I can access programatically ? Thank you.

That app could have an selling my phone option and the second hand user couldn't use it. — Kartik Watwani, Sep 10 '17 at 14:23
Take a look at [this](https://stackoverflow.com/a/2785493/6950238) answer of [Anthony Forloney](https://stackoverflow.com/users/166712/anthony-forloney). — Andrii Omelchenko, Sep 10 '17 at 15:20
It says we should use Device id but it may change on factory reset. — Kartik Watwani, Sep 11 '17 at 02:01

Zeeshan Arif · Accepted Answer · 2017-09-10T19:06:52.803

0

For this purpose, you have to differentiate between devices.

For Android, you can use Device ID

For IOS, You can use vendor ID link.

For IOS : When your app deleted and reinstalled then vendor ID changes so it is better to store your vendor id in keychain using below code.

-(NSString *)getUniqueDeviceIdentifier
{

 NSString *yourAppName=[[[NSBundle mainBundle] infoDictionary] objectForKey:(NSString*)kCFBundleNameKey];

 NSString *applicationUUIDStr = [SSKeychain passwordForService:appName account:@“Your_App_Name”];
 if (applicationUUIDStr == nil)
 {
    applicationUUIDStr  = [[[UIDevice currentDevice] identifierForVendor] UUIDString];
    [SSKeychain setPassword:strApplicationUUID forService:appName account:@"Your_App_Name"];
 }

 return applicationUUIDStr;
}

edited Sep 10 '17 at 19:06

answered Sep 10 '17 at 13:53

Zeeshan Arif

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I strictly want that one account per device thing. People would soon find this thing and could make more than one account per device. – Kartik Watwani Sep 10 '17 at 14:00
Use vendor ID. This is the replacement of UDID which apple provides. – Zeeshan Arif Sep 10 '17 at 14:06
But what about android phones? – Kartik Watwani Sep 10 '17 at 14:07
For Android try Device ID. You have to place device check for this purpose. – Zeeshan Arif Sep 10 '17 at 14:10
How can we find device id ? – Kartik Watwani Sep 10 '17 at 14:24
Your answer seems to be good but I am not sure about vendor Id in iOS. Include about android device in your answer and remove that advertising identifier so that I could mark it as accepted answer. – Kartik Watwani Sep 10 '17 at 14:33
I tried to explain everything in my answer. Hope it will help. – Zeeshan Arif Sep 10 '17 at 19:08

score 0 · Answer 2 · answered Sep 10 '17 at 13:54

0

Im pretty sure these days you can use mac addresses, however if not have you tried IMEI, i have no idea how this would be done.

answered Sep 10 '17 at 13:54

WMTS

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https://stackoverflow.com/q/10831578/4961540 . This question says from marshmallow it is not allowed and what about dual sim phones each sim slot has different IMEI. – Kartik Watwani Sep 10 '17 at 14:05

How can I know my app was previously installed on a phone?

2 Answers2