I'm using RemoteXY since years for different small projects. Recently I started to build a mecanum wheel car ( actually it is an AGV, but let's continue to call it a car ). The issue I had was, to control this car with a wifi or bluetooth controlled remote.
I don't want a cloud connection ( like Blynk ), so RemoteXY is a possible solution.
My setup: using a Wemos D1 Mini, based on ESP8266, as access point and communicating the data via SPI to the main controller for the wheels.
Here is a picture of the user interface

The arc division level indicators on top shows the current for each wheel. The level indicator on the left side is for the battery voltage.
Depending on the positions of the two joysticks, the small "car" is animated accordingly to indicate the direction of the wheels, which is important for a mecanum car.

I hope this is interesting and inspiring for your.
Seventh