IP Connection to an linux device

I´ve following problem. I´m Designer and have a respectable knowledge in frontend. That´s the reason i used ionic. Design and frontend of he app are already done.

Badly we don´t have someone who can help me developing backend. I look now sind many weeks for a solution, but whatever i find, i don´t understand it, or i cannot use it for my problem. It´s a wired situation.

The problem: Phone and Odroid are already in the same network.

When I start my app, i should get access tot he odroid with IP, username and password.

We always stay in the same network and it should work without typing it inside. It´s just for a small group of workers (will not published), so safety is not really important.

It should work a bit like with putty, just that no terminal will open. Different scripts should run trough click functions.

Has someone a code which works like this?

Anyway i think it couldn´t be too complicated, but i have no foreknowledge