bolt-on
n.—Gloss: a business or product line acquired by a company in lieu of the company developing that product or expertise for itself. Note: Also as an adjective. «Although Oracle would like to be considered daring, its strategy of growth-by-acquisition has generated a backlash in corporate software circles, where it is sometimes called a bolt-on company.…“A bolt-on is when you buy it rather than build it yourself.”» —“BEA Systems rejects Oracle’s takeover bid” by Tom Abate San Francisco Chronicle (California) Oct. 13, 2007. (source: Double-Tongued Dictionary)
Further reading
You don’t really need those little rivets on your blue jeans. Those flat metal disks are leftovers from an earlier time, when jeans had to be much more durable. Such decorative elements that no longer serve a practical purpose are called skeuomorphs...
Emily in San Diego, California, wonders about the phrase to dog, meaning “to close and secure” as in to dog a door. In a nautical context, the phrase dog the hatches means to secure them with a bolt or handle designed for that purpose. This phrase...