Yep, katakana ー = extended vowel. ター = たあ, though you’d often just write it as たー anyway. For example, “ramen” in Japanese is ラーメン, but you’ll often see it written らーめん as well. The small っ in katakana is the same, only in katakana: ッ.
You’ll tend to find a lot of technical terms are foreign loanwords. =)
And yeah, I’m not a huge fan of Jisho’s current layout…
Tiny side note, ソフトウェア transliterates to そふとうぇあ – note the small ぇ. ~うえあ has a slightly different pronunciation (though to be fair, it’s an equally valid way of writing it). フィルター to ふぃるたー as well. Note ふい = “fui” but ふぃ = “fi”. There’s a bunch of extra combinations and glides which exist only in katakana to cover all sorts of weird foreign pronunciations.