This is less feasible and you are likely not to use it, but it is still an option. The third and hardest option is to find a vulnerability on the phone and remotely exploit it to gain root access, then you can install all the apps you like, whether silently, through the installer or by any other means. You would need to either have temporary physical access and install the app yourself, or you could social engineer the victim, as Mozes correctly pointed out, although that isn't really a bypass as the user is aware that something is being installed on their device. How can I install it remotely onto targets phone without them knowing? Trying to bypass this is tricky and your options are limited. Did he ever share the APK app with you? I would like it alsoif you have it can you share it with me? I think it uses a java exploit but to me the functions where extremly similar to the same functions in a metasploit reverse tcp. This video is old and I have not watched the whole thing personal life and wat-not. If they read what android states the app will use such as idk sending messages or cost to your bill alarm bells, most will do it without blinking but you get the point. This video pretty much explains how to build a spyphone not the movie sense but a meterpretered exploit that will give you access to well anything.

I'm not sure if it is possible to remotely upload and install as to my knowledge you would need to social engineer them or have physical access to it. There are plenty of tutorials on doing that here but the trick is hiding it. The apk your thinking of can easily be acomplished with metasploit.

Install Keylogger Through Email