In Caynax Hourly Chime when I select chime option a dialog with a Search button appears. But while I have some sound file in my SD it do not show them. How can I choose chime file in this app?
You need to place your audio files in the correct directory structure, as I explained in this answer:
There are special directories you can use to store your custom "noises". The "starting point" (root-of-noises-dir) may be different between devices (so this is rather a generic answer, as I do not own all of them) -- pick one and check if it works, if not, pick the next:
In there, put the directories for the specific events:
Then place your sound files into the appropriate directories. Done. Now you should be able to pick them in your configuration(s).
free app version lists all sounds up to 30 sec. You don't need to place them in specific folder. To refresh list that app uses you can unmount sdcard and place it again and then start app. if you have really lots of sound files it might take awhile to load.