Weebly was interesting because before that Square had their own online store (it went through a bunch of names over time) and they existed concurrently for a while, although I'm not sure if they still do. The codebase was a nightmare and the whole team had abandoned it and moved on to other things, which meant it wasn't getting fixes or updates for a while.
Cash App was not an acquisition, it originated as a hackweek within (what was then called) Square.
Possibly you’re thinking of the Afterpay acquisition?