iOS App: Network Analyzer Pro or System Status Pro: hw monitor for $0.99

Network Analyzer Pro (iOS App)
Network Analyzer can help you diagnose various problems in your wifi network setup, Internet connectivity, and also detect various issues on remote servers. (An advanced tool for network diagnostics, LAN scanning, and problem detection).

System Status Pro: hw monitor (iOS App)
System Status provides graphical monitoring of all the device's resources such as CPU, memory, disk, battery and wifi/cell data usage. It also shows network-related info such as wifi/cell connection details and the routing table. (An advanced tool for monitoring your iPhone and iPad performance).