Mobile Number Validation Apps

I've found some apps that claim to be able to validate mobile numbers and I was wondering if anyone was able to tell me how accurate they might be. Some are free and the last two require purchases (only one of which I was willing to try):

• Lacak Nomor Telepon HLR Lookup: seems OK but only works in Indonesia
• Mobile Number Locator: says it can find the location of an incoming number in India, China, Pakistan or USA and it seems to work for US numbers (I didn't test the other countries) but it doesn't tell which carriers a number belongs to. And has lots of ads in it
• Mobile Number & Phone Location: again it seems to provide location information for US mobile numbers but doesn't give me full number validation.

And two that say they perform HLR lookups, but require purchases:

• Phone Number Lookup Search: I'm not entirely sure what this app is. It seems to be a web page wrapper that offers a report on a mobile number, but I don't trust it to click on any links in it.
• GoodNumber: I bought credit through the Play Store and it seems to perform number validation and returned carrier information for US and UK numbers (says it does a lot more countries, but I haven't tried)
  Those are all the apps I could find; has any one else come across similar apps?