Looks like ACRA uses a simple post. What language do you need it in? For asp.net:
protected void Page_Load(object sender, EventArgs e)
{
StringBuilder err = new StringBuilder();
foreach (string name in Request.Form)
{
err.AppendLine(name + ": " + Request.Form[name]);
}
TextWriter tw = null;
try
{
tw = new StreamWriter("f:\\errorLogs\\error_" + DateTime.Now.Ticks + ".txt");
tw.WriteLine(err.ToString());
}
catch (Exception) { }
finally
{
if(tw != null)
tw.Close();
}
}
Since you are using a "free web host", the location probably isn't valid for you, but this should at least get you pointed in the right direction. There is another post which is similar to yours. Most free web hosts use php.
EDIT:
Here is a basic PHP script (Not tested, but seems OK to me. My PHP is a bit rusty):
<?php
$file = 'postData.txt';
$arr= $_POST;
$fp = fopen($file, 'w') or die('Could not open file!');
foreach ($arr as $key => $value) {
$toFile = "Key: $key; Value: $value \n";
// write to file
fwrite($fp, "$toFile") or die('Could not write to file');
}
// close file
fclose($fp);
?>