What is your web app's cgi type?
Or what is your web app's starting file type?
If it is cgi, you must set the file handle to open file order.
If it was .exe , you must set the command for iOS's DOS version and It call up with dll file to .exe for DOS command.
DOS command is even for any device, in windows , iOS , android has it by mother bord's order to read - or + is 1 or 0's number of 32bit or 64 bit.
If you wanna create application for iphone or android's mobile, you must be sure your DOS version and command line.
If you wanna learn more, you would better to sarch for "DOS COMMAND" on sarch engin.
If It's app is wrong, you must long tap and retouch it's x mark.
If it's app is safe, you can use it.