Besides Yoda and Obi-Wan Kenobi, Qui-Gon Jinn is also supposed to have become a Force-Ghost (even more, he probably taught becoming one to the other two, according to the end of RotS). So, did Qui-Gon's ghost appear anywhere in TFA?
No. He's not in it. Not even in a flashback.
As to why he wasn't in the film, you'd have to ask Jar Jar Abrams but my personal guess it that his character simply wasn't a big enough part of the Prequel trilogy to merit inclusion into a film that was heavily focused on being a retro pastiche of the Original trilogy