Custom keyboard appears with ~5seconds delay

Question

I'm making custom keyboard with obj-c, Xcode 7 (tried 6 too). The issue is that keyboard is loading too slow.
I tried to load completely empty UIInputViewController's view - no changes. I have no xibs, no heavy resources. Please if someone know any solution of this problem, write an answer. user won't be glad to wait every time keyboard lags.

Answer 1

It's a known issue that the keyboard (custom or not) may load slowly the first time it's opened after the app launch.
It happens only in debug mode and should not happen on a release build thanks to the high optimization level.