This repo is for hacktoberfest 2021.
Truecaller is an app which can provide when given. If you want to know the contact calling you, the person with whom the contact is saved, should share it, thereby surrendering his contacts for the "benefit" of others.
The data is crowd-sourced from the millions of users who have downloaded the truecaller app on their smart phones. As part of the end user agreement, the truecaller app asks the user to allow access to the user's address book/contacts on the smart phone.
This data is then uploaded by the app to the company's servers. After going through several data matching/refining algorithms, this data is made available to all truecaller users to search upon.
The story must start from the login screen. If you have already used Truecaller, you might have seen that Truecaller only allows either Facebook, Yahoo! or Gmail to access Truecaller app. If you don't have one you cannot connect to Truecaller database. This is because, Facebook, Gmail and Yahoo! are the most widely used social networking sites that contain a lot of phone numbers and other contact details.
It implies that when you use one of the social sites, your entire contacts including phone numbers, contact names, email ids will be uploaded to a secure Truecaller server. In case you login to the app using your mobile phones then your entire address book will be sent to the Truecaller servers.
These are organized into records and each number will be assigned a Truecaller id. When some one searches the number using Truecaller number search, the caller id associated with that number will be displayed.
So out of all the people who know you and have your contact number stored against your name in their phones - if even 1 person uses the truecaller app, your contact number and name would end up in the truecaller database.
Happy HacktoberFest-2021