Are you missing the key layout you're used to from your computer? This keyboard has separate number keys, punctuation in the usual places, and arrow keys. It is based on the AOSP Gingerbread soft keyboard, so it supports multitouch for the modifier keys. This keyboard is especially useful if you use ConnectBot for SSH access.
Hacker's Keyboard is created by Klaus Weidner and its category is Productivity. Over 5M users downloaded and installed the tool and the latest release was on Nov 26, 2018. People rated this application 4.4 on Google Play.