The service was created in 2011 in the Czech Republic. It is an online forum where the users can share their experience with phone numbers, both annoying (mostly telemarketing, surveys) and useful (e.g. couriers, offices)..
Since the beginning, the service has been received very well, which led to localization into more languages. Nowadays, the forum exists in more than 20 languages and 34 countries throughout the world.
The service is intended for anyone who wants to identify the owner of an unknown phone number. The creators of the forum have also recently created the mobile app Call Insider for Android phones. This app, which is connected to the database of the website reverse-phone-lookup.co.uk, also allows users to automatically block telemarketing numbers.
FAQ
Getting calls from loads of numbers, including this one, since I applied for a job with 'Nationwide Placements UK', on one of the job websites.
Pretty sure it's a fake recruitment site posting lots of ads to harvest CVs and sell the info on. Don't apply for any jobs listed by Nationwide Placements UK.