I don't think TapFly will work in sport mode but you can do  it by manual flight.  I does take some practice and I have only done it in P mode.  It's pretty cool when it works, not so much when it doesn't.
Oh...by the way,  another guy suggested flying it backwards, which is a good idea.  Start moving horizontal just above ground level and fly higher while still going horizontal.  He said you could reverse the video in post but I haven't figured that out yet!