Apps similar to SterJo Netstalker include Portmaster, which is open source with a free version. Other options are simplewall, RethinkDNS, Fort Firewall and Little Snitch. You can choose from more than 10 Firewalls like SterJo Netstalker for Windows, Linux, Mac, Android and iPhone.
Free, open-source privacy suite monitoring all network activity, blocking unwanted connections, using trusted filter lists for ads and malware, enforcing DNS-over-TLS, providing custom app and global rules, and supporting advanced privacy management.
Austria
EU
Simple tool to configure Windows Filtering Platform (WFP) which can configure network activity on your computer.
Kazakhstan
An OpenSnitch-inspired firewall and network monitor + a pi-hole-inspired DNS over HTTPS client with blocklists.
United States
Standalone firewall for Windows 7 and later featuring flexible rules by application, address, or protocol, wildcards, parent process filtering, SvcHost controls, blocklists, bandwidth graphs, traffic stats tracking, speed limits, and real-time network monitoring.
Uzbekistan
Firewall application for monitoring and controlling outbound network connections, notifying users of attempted access, supporting rule-based blocking, real-time alerts on suspicious activity, and preventing unauthorized data transmission on macOS systems.
AustriaEU
Comprehensive Windows software for internet traffic control, enabling users to set bandwidth limits for applications or connections. Offers real-time monitoring, long-term stats per app, and detailed internet usage reports. Ideal for managing data efficiently and enhancing network performance.
CzechiaEU
Minimal Firewall is a portable Windows firewall frontend that alerts users to internet connections without requiring custom kernel modifications or disabling core isolation, striking a balance between TinyWall's security and SimpleWall's functionality.
United States
NetBalancer is an internet traffic control and monitoring tool designed for Win7/8/10.
RomaniaEU
Gufw is an easy, intuitive way to manage your Linux firewall. It supports common tasks such as allowing or blocking pre-configured, common p2p, or individual ports port(s), and many others! Gufw is powered by Uncomplicated Firewall (ufw).
SpainEU
As soon as you’re connected to the Internet, your apps can send whatever they want to wherever they want, unnoticed by you, because all of this happens invisibly under the hood.
AustriaEU
Bouncer is an application to help you choose the correct firewall zone for wireless connections. When you connect to a new network, Bouncer will open a window prompting you for what kind of network (eg home, public, work) it is.
All the functionalities of a modern Next-Gen firewall in few clicks: MultiWAN, Deep Packet Inspection, VPNs, Threat Protection.
ItalyEU
