Too slow to be useful (on iPad 3)

I bought this app because I was looking to get a very responsive tuner that could follow the notes while playing my instrument (cello). Since the description claims a sub-second responsiveness, I gave it a try. I own an iPad 3, and it is running at about two frames a second. To catch up from my upper A string to the lower C string, it takes like 5 seconds. I dont know if it is because of the retina display with many more pixels to draw or what, but this app is totally useless now. Please fix it, because it seems otherwise quite promising.

Meline Divine about Tuner!!, v1.5