The official free version of Truecaller still provides excellent caller ID and spam protection.

Here is a blog post outlining why you should stick to official versions and what the actual risks are.

Truecaller uses server-side verification to detect unauthorized versions of their app. If their system flags you for using a cracked APK, you risk a of your phone number from the service. You’ll lose the ability to use the official app even if you decide to pay for it later. 4. No Updates or Support

"Cracked" apps are a common delivery method for spyware that can record your calls, read your SMS messages, or access your camera.

Truecaller frequently offers regional discounts or "Family Plans" that make Premium highly affordable.