Network tools orbit two things, connecting and diagnosing: proxy and VPN clients, tunnels and NAT traversal, firewalls, network monitoring and packet capture, speed tests, download managers, instant messaging, cloud-storage sync, plus browsers and scrapers.
Proxies and tunnels are the densest group. What separates them is protocol support (HTTP/SOCKS5, WireGuard, VMess and the like), whether you have to run your own server, and whether they offer routing rules. Those three tell you more than raw speed does.
For a specific problem: to reach a machine on your home network, look at NAT Traversal; to inspect traffic, Network Monitoring and Packet Capture; to measure bandwidth, Speed Tests; to queue up downloads, Download Managers; to sync files across devices, Cloud-Storage Sync.
Proxies, tunnels and scrapers carry different legal requirements in different regions, so check local rules before use.