I think Atlassian does a good job of not killing off apps it acquires (anyone have examples?). They just rebrand them and smoosh them into their whole suite of stuff they've bought.

Years ago I was talking to a Melbourne dev who said they've made very little (Jira and Confluence I think?) and the rest of it they've just bought and rebranded?

Yahoo likes to kill apps and take devs, like Astrid Tasks.