Apps like PortKnocker

Here are some great alternatives to PortKnocker by Stephen Paine :
Packet Injection
Packet Injection
★3.8
XTextureExtractor
XTextureExtractor
★3.6
Mahjong VirtualTENHO-G!
Mahjong VirtualTENHO-G!
★4.5
AG Displays
AG Displays
★3.8
Resolution Check (ResCheck)
Resolution Check (ResCheck)
★4.0
Hand fonts for FlipFont
Hand fonts for FlipFont
★3.3
Resolution Changer — Uses ADB
Resolution Changer — Uses ADB
★3.6
Screen Resolution Changer: Dis
Screen Resolution Changer: Dis
★3.3
Pixels: Resolution+DPI Changer
Pixels: Resolution+DPI Changer
★4.6
DPI Converter PPI Calculator
DPI Converter PPI Calculator
★4.1
DPI Screen Info
DPI Screen Info
★3.6
Pixel Clock Widgets & Themes
Pixel Clock Widgets & Themes
★3.8
Screen Size / Info / Dpi
Screen Size / Info / Dpi
★4.3
Display Tester Pro Unlocker
Display Tester Pro Unlocker
★4.4
Big dgt mod 5M Watch face
Big dgt mod 5M Watch face
★4.4
Display Calibration
Display Calibration
★3.9