What data can an iOS app get from an iOS device?


I am new to the forum.

I am interested in what data an iOS app get from an iOS device, both apps that follow Apple guidlines, and also what is technically possible (if slipped past the checking process). I ask as a user (personal iPhone) and a business user (work iPhone), as I would like to know what personal data my device is leaking, and obviously I have a duty of care to my customers, to protect their data.

Clearly there are many experts on here. I read such conflicting information on the regular Apple forums.


@novice Thanks very much for your question!

I think it’s easier to answer a much more specific question by stating which data in particular is accessible in iOS? Because the Apple ecosystem is a closed system unlike the Android platform which is open-source, there are many checks and balances that protect users data on a device. It honestly would be much easier to answer a question that identifies something in particular you are concerned about (e.g. contact list, battery life, etc).

Having said that, when you’re using a work-issued phone, the rules change because many companies who deploy devices to their employees using a Mobile Device Management (MDM) service (e.g. AirWatch, MobileIron, SOTI) to control the usage of the devices. These platforms allow the company to restrict usage of the devices in different ways (e.g. installation of personal apps, usage of the web).

I do also wish to point out (and I realize this is a serious tangent) that jail broken devices are obviously much more susceptible, but this is also why devices that are jail broken may not download updates to the iOS they are running, and download apps from the app store. Because the app store approval process is rigorous and thorough, apps don’t typically “fall through the cracks” so to speak, especially if they are violating a users privacy. Even if, for some obscure reason they were to evade detection, if an app was violating these guidelines then Apple would most definitely remove them once users complained.

Going back to my original point, it’s best to ask specifically which device data you are concerned about, and also if there is a particular app you are trying to develop to access this data (and if there are possible workarounds).

I hope this helps.

All the best!

Thank you syedfa for your reply.

I used to read some of the Privacy Notices, and some of them seemed to imply they could get everything except your inside leg measurement! On another forum, it was hinted that these privacy notices, are there to cover the developer completely, apply to iOS, Android and window apps and may not really relate to what information they can get from an iOS device.

The phones are not jailbroken, and its my own business, hence my concern with client data privacy.

So for example, if I use a third party spreadsheet, is the data in that spreadsheet readable by the app developer? Can developers see our phone numbers and email etc?


@novice Thanks very much for clarifying :slight_smile:

With respect to files on your device, as an iOS developer I don’t have the means of gaining access to the data that lies on a spreadsheet on your phone. iOS does have a Contacts API which does allow developers a way to get access to your contacts list on your iPhone, but not a way to actually get a users phone number for the actual device itself. Apple does not provide an API to do this, so this is not possible. With respect to email, Apple does allow developers to compose and send email using the default email account, but does not allow a way for developers to gain access to the users emails that they have already received.

I hope this helps!

All the best!

Thanks for getting back to me.

With regard to contacts on the phone, would that always throw up a dialogue box asking if I want to give permission. Again with the composing and sending email via my email account, would I have to grant permission via a dialogue box. Finally, I know apps are sandboxed, so you couldnt access data on a spreadsheet, but could the developer of the spreadsheet access the data?

Many thanks

With respect to gaining access to a user’s email, it’s simply not possible since Apple doesn’t provide the means to do it, so it’s not even something you would even have to grant permission for. A developer can only access what Apple allows the developer to access, and the users email is not something that can be made available, and the same goes for the phone number.

With respect to gaining access to the contacts, I think the issue here is what apps are you downloading that would allow them access to your contacts? One thing that Apple is very careful about is allowing apps to gain access to users data without them knowing, so data from the user can never be granted to an app automatically without consent from the user. This is the case with using the user’s pictures stored on their device as an example. I can’t as a developer by default, help myself to the user’s pictures without gaining the user’s permission first.

As for the issue of the spreadsheet, I am not sure I understand this question. If you have an app that allows you to build a spreadsheet, then I would think that the one who makes and stores the spreadsheet would be allowed to retrieve that spreadsheet, and thus, access the data contained in it. is this what you mean?

Hello syedfa,

Sorry I was confused when you said “Apple does allow developers to compose and send email using the default email account” that someone could send emails as if from me. But I assume it means I can click on a contact button, that generates an email addressed to the developer - stating my Hardware and Software, but only sent after I pressed send?

With regard to the spreadsheet, does Microsoft (excel) or Mobisystems (OfficeSuite) have access to data placed in their spreadsheets if no cloud storage is selected?

Thanks again.

I believe you’ve misunderstood what I said. When I said “Apple does allow developers to compose and send email using the default email account”, what I’m referring to is a developer is able to build an app that is able to compose an email using the default email account, and allow the user to send it. Many apps allow the user to send an email, and this could be either to a friend, or to allow the user to contact the company who built the app. In which case, the developer would provide THEIR email address to the user. I also wish to point out that I never stated that this email would contain the user’s hardware/software information. The email the user is sending could contain a picture that they are sharing from social media, or perhaps an article that they’ve just read from the Internet, etc. Developers are unable to derive hardware/software information from an email composed from a smartphone. At all.

As for Microsoft, or Mobisystems, I think it is safe to say that without a connection to the cloud, the companies are unable to read the data from individual spreadsheets.

I hope this helps.

All the best!

Thank you syedfa. I know you never stated that this email would contain the user’s hardware/software information, its something I have seen when contacting developers from an app (probably helps with any fault finding.

So from what you say, iOS does seem more secure than others on even Apple leaning general forums state. I have a document on Google analytics, (which many apps use), which I will now read.

Thanks again, its been informative.

Hi Richard (@novice),
I understand your concerns, I believe that @syedfa has helped you with most of the questions. I wanted to answer this a bit differently, so here goes.

Apple has a lot of things in place that disallow a developer to do things unacceptable for the user. In fact (I think) starting from iOS 9 onwards they are adding more and more permissions that the user has to accept to allow the app to access hardware on the device and the user is made aware of these choices (ONLY ONCE - at the start of the app). These can be changed in the settings app under various settings but mainly privacy.

Even things like sending emails, apple allows the developers to compose and create an email, but it is the user that has to then click send, there is no automatic send from the mail compose UI.

Now comes the interesting part, if you have given permissions to the app to access certain areas like Camera, Microphone, etc then… a developer can determine from the app what the user is doing by looking at the orientation data, the accelerometer data and the camera and microphone. Felix Kraus has a couple of articles and sample code to demonstrate how this is done.

Sending an email can be done by bypassing the mail composition UI by accessing a SMTP server directly and the user can be asked to create a profile and enter their email address, following that any data created in the app, that is accessible by the application can be (in theory and yeah, in practice) be send without the user knowing about it.

From the app, the developer can create automatic networks even when there is not internet/wireless only via the Bluetooth interface, (There was an app called FireChat [I think] that created peer-to-peer network to access and send messages.

So the point I am trying to make is that there are ways that a smart developer can - however it all depends on what advantage they derive by doing so, majority of the developers only try to mine user data for marketing purposes (the new currency) while very few would be interested in stealing data. They can also create a backdoor that allows them to query the application’s sandbox, but I guess that it is caught by the testers at Apple before releasing the app or by some astute user and then the malicious app is removed from the store. If you have a custom or a very low profile app, well there is a chance that you would never know.

Hope that has provided you some information not just scared you,


Thank you jayantvarma, thats most interesting. So whilst iOS is fairly secure Apple could still do more.

I frequent many of the standard Apple user forums, and there is so much conflicting information (especially from FanBoys and Haters of Apple), much of it probably urban myths, so its great to speak to actual developers.

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