In a way, yes. You’ll have to learn about the way Truecaller works to understand this.
Truecaller works on a methodology called “crowdsourcing “. Now what is crowdsourcing? How is Truecaller able to tell you the name of a caller not in your contacts list? Simply, by ‘asking’ it to someone who has the number in their contacts list.
Every user that uses the Truecaller app submits his contact list to Truecaller’s servers. Now if any of these contacts calls you and you don’t have that number saved in your phone, Truecaller tells you who it is by looking at the information stored on their server by their other users. This is called as crowdsourcing.
The privacy concern here is that the app takes up all your contacts and you don’t have a choice to allow them or not. I understood the way this app works as soon as I first installed in on my phone. Since then, I have never used it again because I don’t want them to ‘spy’ on me like this.
So by literal definition, you can’t call it a complete spyware, but it does take your information like location, contacts, etc. so you have to decide if it is a concern for you or not. For me, it is.
PS: Almost every app you use on your phone is doing this with or without your knowledge. Facebook does it, Google does it. It’s actually very difficult in today’s world to use the internet and not be spied upon by these huge tech giants. So we’re all just compromising with our privacy and safety