I don't know what makes you think F9 returning a tilde is "correct", but if you want a tilde, you should use the tilde key.

Function keys are mostly undefined, based on the differences in the client-side hardware you are using, the client-side software you are using, the server-side software you are using, and the server-side hardware you are using.

Tilde on unix:hpux and / or solaris
When I read Google play policy, I have a question in this sentence.

An app downloaded from Google Play may not modify, replace or update its own APK binary code using any method other than Google Play's update mechanism.

This means developsers can't use self-modifying code??

For example, when users run a my app for the first time, my app modify its binary code. 

And if I use it, can I upload my app using self-modifying code??
