Yep, we used Unity. It gets a hard time sometimes, but if you treat it just like you would any other toolset/language/tool, it really is pretty great. It's also pretty easy to jump into, and have something running quick (Hello World style), though definitely takes some time to get used to the different paradigms and the "Unity Way".
I may be (probably am) missing the reference -- but my first instinct would be to check out TextMeshPro for something like that, especially if you want to keep draw calls low/when performance is a supreme concern.
Apologies if it's just a reference I totally missed though! =)