In this explanation you get a very simple way to connect a ESP8266 WiFi board to the RoboRema App.

You need:

Android or Apple device to run the RoboRemo app.
Install the RoboRemo app.
Install Arduino IDE
Install Arduino ESP8266 library.
ESP8266 board like Wemos D1 mini or NodeMCU. (for ESP-01 you need additional USB to seriel adapter, wires and more, not so handy)
MicroUSB cable

Possibly:

Wemos D1 Mini library and examples.
Additional shields.

The intention of this instructeble is to give you the foundation with the connection so you can add more functionality by yourself.

Help with installing Arduino: Programming-the-WeMos-Using-Arduino-SoftwareIDE

Wemos Arduino help and Wemos Shields library

Step 1: Coding Your Sketch

Download the sketch and copy this code to your Arduino IDE.
Look if the *ssid = "RoboRemo" fits your needs or change it. (don't use the SSID from your local network)
If you want add a password by *pw
Choice by Tools => Board the right board (Wemos D1 mini)

RoboRemoEasyServer_01.ino
Download

Step 2: Set COM-port

Look to the Ports that are connected (Port:).
Connect the ESP8266 (Wemos mini) with the microUSB cable.
Select the COM-port that is last added.Upload your sketch.

Step 3: Make Connection

To make connection between the ESP8266 and RoboRemo there are two steps.

1 Device WiFi

We made from the ESP8266 a Wifi-server. So you have to set the device - WiFi - settings to RoboRemo or the name you chance it. So go to the WiFisettings from your device.

2 RoboRemo connect

From the RoboRemo-app :

menu => connect => Internet (TCP) => other => fill in IP-adres. In the scetch is given : 192.168.0.1:1234

The WiFi IP will be remember so the next time you can easy click on the right IP.

If there is a problem you have to get the IP from the serial monitor.

Arduino => Tools => Serial monitor.
Reset the ESP8266 or reconnect it.
Wait until the IP is given.

It can by usefull to change the IP in the Arduino sketch. For example in classroom with more ESP's.

Step 4: Setup the RoboRemo App Interface

Now the right program is running on the ESP8266 and the connection is made we can setup the buttons for controling the IO-pins.

For more instructions download the l RoboRemo manual

Choice:

Menu => edit ui => tap anywhere on the screen (new menu pops up) => choice button => drag the button (pick up on the left top corner) to the place you want => resize the button if you want (right bottum corner).
Tap on the button so a menu appears => tap on "set press action" => enter a A => tab Ok. => tap on "set release action" => enter a 1 => tab "Ok"
You can customize the button by color, text etc..
Leave this buttonmenu.
tab the "menu" button. => select "don't edit ui".