Hacker’s Keyboard hasn’t had a real release in about 5 years, so it can be slightly buggy.
Unexpected Keyboard is pretty good. It’s got the complete keyboard layout available including stuff like Control and Function keys, so I think it’s an acceptable replacement. It uses swipes to type other keys, which I’m not sure if I prefer, but it works well enough. I set the swipe distance higher because I would accidentally swipe from time to time.
I’ve had it freeze up on me several times, where I had to reset the app to get it working again. It works most of the time, but I wouldn’t recommend it yet for general use.