Hiya creepily requires access to all of my contacts, which I think they transmit to their servers for vaguely specified reasons.
Truecaller creepily requires my name, phone number, and email address to add to their directory, which I think might allow people to find my phone number under vaguely specified conditions.
Nomorobo isn’t creepy about anything, but costs $2/month with an in-app-purchase subscription.
I had Hiya installed for weeks and it never identified a single spam call, during which time I got about ten. I followed all of their voodoo troubleshooting steps, but it just never worked, so I deleted it. (Too bad I can’t un-send them my contacts. Thanks a lot.)
I had Truecaller installed for a few days, and it correctly identified two spam calls with no drama or voodoo required. It just works.
When I learned about Nomorobo from readers and saw how creepy it wasn’t, I deleted Truecaller immediately and subscribed to Nomorobo, and it works great.
A few days ago, after a 100% success rate for a couple of weeks — every spam call (and zero non-spam calls) identified before I answer — I enabled the option to send spam calls directly to voicemail.
Now, from my point of view, I just don’t get spam calls anymore.
To me, that’s $2/month very well spent.