badoo-likes-keyboard.js

// Probabilities
const getRandomNumberOneToHundred = () => Math.random() * 100;
const keys = {
	arrowLeft  : { key : "ArrowLeft", keyCode : 37, code: 37 },
	arrowUp    : { key : "ArrowUp", keyCode : 38, code: 38 },
	arrowRight : { key : "ArrowRight", keyCode : 39, code: 39 },
	arrowDown  : { key : "ArrowDown", keyCode : 40, code: 40 },
	one  : { key : "1", keyCode : 49, code: 49 },
	two  : { key : "2", keyCode : 50, code: 50 }
}
const simulateKeyEvent = (eventName, eventData) => {
	var keyEvent = new KeyboardEvent(eventName, {
		char : "", 
		shiftKey: false,
		bubbles : true,
	    cancelable : true,
	    ...eventData
	});	

	document.body.dispatchEvent(keyEvent);
}

// The logic
const createLike = () => {
	getRandomNumberOneToHundred() <= 70 
		? simulateKeyEvent('keyup', keys.one)
		: simulateKeyEvent('keyup', keys.two);
	
}

// Here is where magic happens
setInterval(createLike, 1000);