|Developer(s)||True Software Scandinavia AB|
|Initial release||23 September 2009|
|Operating system||Android, BlackBerry OS, iOS, Series 40, Symbian, Tizen, BlackBerry 10, and Windows Phone|
|Type||Telephone directory, caller ID, spam blocker|
Truecaller is a smartphone application which has features of caller-identification, call-blocking, flash-messaging, call-recording, Chat & Voice which uses the internet. The service requires users to provide a standard cellular mobile number for registering with the service. It was developed by the Swedish company True Software Scandinavia AB. The app is available for Android, iOS, BlackBerry, Symbian, Windows Mobile, and Windows Phone.
It was initially launched by BlackBerry on 1 July 2009. After good response from users it launched for Symbian and Microsoft Windows Mobile. It was released for Android and Apple iPhone on 23 September 2009, for RIM Blackberry on 27 February 2012, for Windows Phone on 1 March 2012, and for Nokia Series 40 on 3 September 2012. As of September 2012[update] Truecaller had five million users performing 120 million searches of the telephone number database every month. As of 22 January 2013 Truecaller reached 10 million users. As of January 2017 Truecaller had reached 250 million users worldwide.
On 18 September 2012, Techcrunch announced that OpenOcean, a venture capital fund led by former MySQL and Nokia executives (including Michael Widenius, founder of MySQL), were investing US$1.3 million in Truecaller to push Truecaller’s global reach. Truecaller said that it intended to use the new funding to expand its footprint in "key markets"—specifically North America, Asia and the Middle East.
In February 2014, Truecaller received $18.8 million in funding from Sequoia Capital, alongside existing investor OpenOcean, Truecaller chairman Stefan Lennhammer, and an unnamed private investor. It also announced a partnership with Yelp to use Yelp's API data to help identify business numbers when they call a smartphone. In October of the same year, they received $60 million from Niklas Zennstrom's Atomico investment firm and from Kleiner Perkins Caufield & Byers.
On 7 July 2015 Truecaller launched its SMS app called Truemessenger exclusively in India. Truemessenger enables users to identify the sender of SMS messages. This launch was aimed at increasing the company's user base in India.
In December 2019, Truecaller announced it plans to go public in an IPO on 2022. 
Security and privacy issues
On 17 July 2013, Truecaller servers were allegedly hacked into by the Syrian Electronic Army. The group claimed on its Twitter handle to have recovered 459 GBs of database, primarily due to an older version of WordPress installation on the servers. On 18 July 2013, Truecaller issued a statement on its blog stating that their website was indeed hacked, but claiming that the attack did not disclose any passwords or credit card information. On 23rd November, 2019 Indian-based security researcher Ehraz Ahmed discovered a security flaw that exposed user data as well as system and location information. Truecaller confirmed this information and the bug was immediately fixed.
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- "Truecaller in 2017". Truecaller Blog. 2017-01-18. Retrieved 2017-11-30.
- Lomas, Natasha (September 18, 2012). "Open Ocean Invests $1.3M To Push Crowdsourced Directory Truecaller's Global Reach". TechCrunch. (TechCrunch was owned by AOL as of 2012). Archived from the original on September 20, 2012. Retrieved July 24, 2017.
- "Investor in Community and Open Source Business". Open Ocean Capital. 2012-09-19.
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- Clayton, Nick (2012-09-20). "Truecaller Collects $1.3 Million for Crowd-Sourced Phone Book". Tech Europe - Wall Street Journal.
- Lomas, Natasha (2012-09-18). "Open Ocean Invests $1.3M To Push Crowdsourced Directory Truecaller's Global Reach". TechCrunch.
- Crook, Jordan (2014-02-06). "Truecaller Lands $18.8M Series B From Sequoia, Partners With Yelp To Verify Business Numbers". Tech Crunch.
- "Sweden's Truecaller clinches $60 million in venture capital funding". Reuters. Retrieved 8 October 2014.
- Agarwal, Amit (2015-07-07). "Truecaller Launches SMS App In India, Aims 150 mn Users Base". Digital World.
- Rolander, Nicolas (2019-12-18). "Truecaller Branches Out to Fintech Ahead of Potential IPO". Bloomberg.
- Selvan, Sabari (2013-07-17). "Truecaller Server hacking". eHacking News.
- "Truecaller Statement post hacking". Official blog. Truecaller. 2013-07-18.
- "Researcher Discovered A Critical Security Flaw In The Truecaller App". Mashable India. Retrieved 28 November 2019.
- "Security Flaw In Android, iOS Phone App: 'Immediate Fix' For 150 Million Users". Forbes. Retrieved 27 November 2019.