What are some alternatives?
When comparing NetNut.io and Multiloginapp, you can also consider the following products
Luminati.io - World's largest proxy service with a residential proxy network of 39M IPs worldwide and proxy management interface for zero coding.
Session Box - Using websites with multiple accounts at the same time is made easy.
ProxyRack - More than 1,200,000+ unique monthly HTTP & SOCKS private proxies available.
Firefox Multi-account Containers - Sign in to two different accounts on the same site
Oxylabs - Data center proxies, residential proxy, Real-Time Crawler
Multifox - Multifox is an extension that allows Firefox to connect to websites using different user names.