You can say 'though' at the end of a sentence to mean approximately the same as but at the beginning, but 'although' can't be used that way.
He's very smart. He's not a genius, though.
You can say 'as though', but not as 'although', to mean as if in discussing similarities.
He acted as though he were dreaming.
You can say 'even though', but not 'even although', to mean despite the fact that.
Even though he was nervous, he gave the speech without a mistake.
In most other situations, although and though are equivalent.