Multifunctional reference app:

1. MNP: allows you to find out the region and operator of the telephone number, as well as the fact of transferring the mobile number from another operator. Works for both mobile (DEF) numbers and landline (ABC) numbers.

2. MAC: allows you to calculate the manufacturer of the network equipment (module) by MAC address.

3. Whois: allows you to find out the ownership of the IP-address (network) or ASN.