I recently got a Motorola Moto E (2nd Generation) and was looking for a terminal app I could use both with a non-root version of BusyBox on the phone and as an ssh console to other machines. Turns out open source Termux fits the bill, at least for me, perfectly.
Termux is advertised as a “terminal emulator and Linux environment bringing powerful terminal access to Android”. By default it sets up a minimal Debian/Ubuntu derived Linux environment rooted in the application’s own data folder. The default shell is bash, but using the included apt package manager others can be installed and configured. Among the packages available in the Termux repository are openssh, vim, wget and nmap. None of the versions of BusyBox that I could install without root privileges included that last one, which saves a lot of space over some of the graphical network security tools I’d previously used on Android.
The Termux console itself is one of the nicer terminal emulators for Android. I found that it worked best when paired with the Hacker’s Keyboard as the current keyboard, providing real ESC, CTRL and ALT buttons when in landscape view.
Previously, I had for many years owned a really cheap Huawei handset that was frankly under powered for use as anything but a phone and e-mail browser. At one point I had gone through the ordeal of rooting it and trying out BusyBox. Things worked well enough, but running my phone rooted as anything more than a short term experiment didn’t seem wise. As a result I wound up restoring it to its factory defaults using a special image provided to the community by a very kind Huawei engineer. This time around I decided to do as much as I could without resorting to rooting the new phone (the one nagging problem I have with the phone, its refusal to relocate apps from internal to external storage, may still require rooting to fix). Termux helped me along in that effort.