While there are a variety of telephone call filtering solutions for smartphones, including the stock Google Phone app for Android, cross-platform services such as Truecaller have also carved out their own place in the segment. In fact, Truecaller has been made available for Android, iPhone, BlackBerry, Symbian, and Windows phones during its lifetime.
For most people, the primary purpose of Truecaller has been to help users manage their incoming calls via local blocklists in addition to crowdsourced spam lists, a payment feature has also been made available for those in India for the last two years on an opt-in basis. However, in the latest update to its app, Truecaller ended up registering users to its payment service without gaining their permission, courtesy of a silent text message sent by the app.
With respect to the blunder, Truecaller made the following announcement:
As per the developer's announcement, users can manually revoke UPI registration from within the app but it does demonstrate that privileged apps are not immune to causing significant headaches for their install bases. In the meantime, Truecaller has withdrawn the errant version of its app and is working on a patched version which "will be available shortly".