Is there an iOS API for accessing call logs?
It is not possible to extract the call log programmatically.
First of all Apple officially does not expose any public API to access the call log. That means you can hack all you want to access the call log(Using private API's) but when submitting your app to Apple by sure it will be rejected.
Regarding the app you have mentioned(quickRemainder)
It gets the call log using a cvs file or a text file. It is not taking the info via device calllog db.
Extract from their app description.
You can import text or cvs files containing phone calls into this app.
TrueCaller does not get the call log they just use the app to search the contacts and update the contacts with info they got. They are not reading the callogs
Update: Apple has introduced framework called Callkit. Though you cannot access all the call log, you can have some control over calls like
Identifying incoming calls
Blocking calls
etc
https://developer.apple.com/reference/callkit
call logs on iOS devices
There is no way to access this data on non-jailbroken device.
Reading call history in iPhone OS
Unfortunately you can't access the call history. The only User Data you have API access to is the address book. You can also access photos/pictures but only by starting an iPhone-controlled dialog that allows the user to choose a single image.
It's a bit sucky, hopefully this will be expanded in future versions.
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