Unreal Engine Run Counter from the Editor (to keep track of how many times you run/launch/playtest the game during development)

RunCounterGameInstance.cpp

#include "Core/YourGameInstance.h"

void UYourGameInstance::Init()
{
	Super::Init();
  // Do stuff..

#if WITH_EDITOR
	FString FilePath = FPaths::ConvertRelativePathToFull(FPaths::ProjectDir()) + TEXT("/GameLaunches.txt");
	FString LoadedFile;
	FFileHelper::LoadFileToString(LoadedFile, *FilePath);
	int32 GameLaunches = 1;
	
	if (!LoadedFile.IsEmpty())
	{
		GameLaunches = FCString::Atoi(*LoadedFile) + 1;
	}
	
	LoadedFile = FString::FromInt(GameLaunches);
	
	FFileHelper::SaveStringToFile(LoadedFile, *FilePath, FFileHelper::EEncodingOptions::AutoDetect,
	                              &IFileManager::Get(), EFileWrite::FILEWRITE_None);
#endif
}