I'm not sure why, but this doesn't return the correct value sometimes:
File.Exists( "/system/app","11-11-11-10h-56m_9340_9258_answers_obfuscate-release.apk")
I can clearly see the file exists via adb shell and root explorer. But i'm getting a false instead of true.
My only work around at the moment is using shell commands.
It would also be nice to add another File.Exists(FullPath as string) instead of 2 params even though it's no biggie, just convenient sometimes.
You could reproduce it probably by creating a new file with that same name in root explorer, then trying to check if it exists. Perhaps it's something funky in the filename that was unexpected.