I've recently switched from Windows to Ubuntu and I don't miss anything except for one program named PhraseExpress. With it, you can create shortcuts for words, or fix spelling mistakes you make often, automatically.
yuo → you
rfg → Rindfleischverpackungsettikettierungsgerät
==> → $\Rightarrow$
and stuff like that. I haven't found a replacement for it on Linux, yet.
Would it be appropriate to ask for a program similar to that on Ask Ubuntu?
Software recommendation questions are fine here; we just ask that they be sufficiently specific and detailed. For example, there could be a brief description of the use case or of the features required. You have included sufficient detail in your question here about what you need the software to do, so it looks like you're all set to ask a good question about it on the main site :)