They're the two most common prefixes in software, they solve the same problem, and they are not interchangeable.
get says buy this
It's an acquisition word. It suits a thing you obtain — an app, a device, a box that arrives. It carries a faint whiff of a landing page, which is fine when you have one.
use says work with this
It's an adoption word. It suits tools, platforms and anything with a workflow. It reads calmer and slightly more credible for B2B, and it ages better.
Which to pick
- Selling something people buy once: get.
- Selling something people work in daily: use.
- Not selling anything yet: use, which makes fewer promises.
One thing to avoid
Don't run get on the domain and use on the handles. If you're taking a prefix, take the same one everywhere — a split prefix is worse than either choice.