I write tools to interact with games - ctrl+p to do a price lookup for item under mouse, track which cards have been played/are in your deck, that sort of thing - and it'd be really useful there. DLL injection is kind of a pain (and it can be detected as cheating, which this little framework probably doesn't solve), so the fastest route for prototyping ideas tends to be AutoHotKey or something else that can spawn tooltips easily on top of D3D windows. Obviously that has tons of drawbacks, so if this is quick & easy and runs on a 'real' platform like .NET, it'd be a lot more powerful.