Would be great to have a localhost terminal to be able to ping and do other stuffs.
You can do this, but only on jailbroken device. And even then there is a trick to it. User "mobile" which runs all userspace on iOS does not have the rights to open tcp sockets to localhost:22 even if you jailbreak. So you must bind your sshd to any port above 1024
While this idea is both great and achievable, it wouldn't be acceptable to put it on the App Store. Apple insists that all App Store apps are heavily sandboxed, and a localhost tty would violate this policy. However, this may see the light of day on a jailbroken or profiled device.
Yes! I use this on the Mac version by having a server host just localhost but that didn't work on iOS