SuperF4 - SuperF4 kills the foreground program when you press Ctrl+Alt+F4.
iMyFone iTransor for WhatsApp - iMyfone iTransor for Whatsapp is the best transfer tool which can help you transfer Whatsapp cross-device.
Advanced Task Killer - This tool is also known as ATK. It is a tool to kill applications running.
iMazing - iMazing lets you transfer music, files, messages, apps and more from any iPhone, iPad, or iPod to a computer, Mac or PC. Manage and backup your iOS device simply without iTunes. (was DiskAid)
ProcessKO - ProcessKO free download: Process killer software for Windows. Safe PC download for Windows 32-bit and 64-bit, latest version.
Syncios WhatsApp Transfer - Syncios WhatsApp Transfer is both phone to phone WhatsApp transfer and WhatsApp backup and restore tool. It not only supports to transfer WhatsApp chats iOS and Android devices, but also supports backing up your WhatsApp data to PC and restore .