Thorn, pronounced like 'th' in the word 'thorn', and eth (crossed 'd') pronounced like 'th' in 'there' were used in Old English, or Anglo-Saxon. This is the standard pronunciation in the West Midland dialect of OE, which is more or less the standard, since that's the one that got written down most often. In other dialects thorn and eth might have been pronounced the opposite way, or both the same. I believe they are also used in Icelandic.

There is no 'th' sound in German. Some words used to be spelled with 'th', like the verb thun which is the spelling in the Luther Bible, but the 'th' was pronounced like 't' and since the beginning of the 19th century, the 'th' has been replaced by 't', so the verb is now spelled 'tun'.