I think the appSettings section is a pretty neat solution for something as simple as your example, and I use this frequently over creating config sections, when no hierarchy is required. I do however find the following snippet useful to add consistency to the way appSettings are used, adding some typing, building in the idea of whether the setting is expected to be found in the .config file, and providing the ability to specify a default value.

public static class AppSettingsHelper
{
    private static TReturnType LoadAppSetting<TReturnType>(string name, bool required, TReturnType defaultValue)
    {
        // Check for missing settings
        if (!ArrayExt.Contains<string>(ConfigurationManager.AppSettings.AllKeys, name))
        {
            if (required)
                throw new ConfigurationErrorsException(string.Format("Required setting missing: {0}", name));
            else
                return defaultValue;
        }

        // Read the setting and return it
        AppSettingsReader reader = new AppSettingsReader();
        return (TReturnType)reader.GetValue(name, typeof(TReturnType));
    }

    //simple example boolean property
    public static bool IsSomethingSet
    {
        get
        {
            return ApplicationSettingsHelper.LoadAppSetting<bool>(
                "settingName",
                true,
                false);
        }
    }

    //simple example boolean property
    public static bool SomeCount
    {
        get
        {
            return ApplicationSettingsHelper.LoadAppSetting<int>(
                "someCount",
                true,
                0);
        }
    }
}

Use like this:

if (AppSettingsHelper.IsSomethingSet)
{
    Console.WriteLine(AppSettingsHelper.SomeCount);
}

I think the appSettings section is a pretty neat solution for something as simple as your example, and I use this frequently over creating config sections, when no hierarchy is required. I do however find the following pattern useful to add consistency to the way appSettings are used, adding some typing, building in the idea of whether the setting is expected to be found in the .config file, and providing the ability to specify a default value.

public static class AppSettingsHelper
{
    private static TReturnType LoadAppSetting<TReturnType>(string name, bool required, TReturnType defaultValue)
    {
        // Check for missing settings
        if (!ArrayExt.Contains<string>(ConfigurationManager.AppSettings.AllKeys, name))
        {
            if (required)
                throw new ConfigurationErrorsException(string.Format("Required setting missing: {0}", name));
            else
                return defaultValue;
        }

        // Read the setting and return it
        AppSettingsReader reader = new AppSettingsReader();
        return (TReturnType)reader.GetValue(name, typeof(TReturnType));
    }

    //example boolean property
    public static bool IsSomethingSet
    {
        get
        {
            return ApplicationSettingsHelper.LoadAppSetting<bool>(
                "settingName",
                true,
                false);
        }
    }

    //int property
    public static int SomeCount
    {
        get
        {
            return ApplicationSettingsHelper.LoadAppSetting<int>(
                "someCount",
                true,
                0);
        }
    }
}

Use like this:

if (AppSettingsHelper.IsSomethingSet)
{
    Console.WriteLine(AppSettingsHelper.SomeCount);
}