The correct way of adding samples to your reactable mobile in iOS is the following:
If you have iTunes, I would reccomend to take this steps
1- Without adding any folders, drag your samples into iTunes file sharing, into your documents
2- Start reactable and go into Setup --->Manage sounds
2.1- If you want to create a Folder structure, look at the bottom left a bar that appears with a button labeled "New directory", click it and give it a name after the dialog pops up. If you want more levels you should repeat this process inside of the newly created folder.
3- Scroll down to the section labeled "Sound files". The files you added through itunes should be there already.
4- Click the "Edit" button ( on the top right corner) and select all the files you want to move to the folder
5- Click the "Move" button and it should scroll to where your folders are. To navigate further down, instead of selecting the name of the folder, click on the blue arrow on the side, until you see the folder where you want to put the samples. When you see it, click on the folder name. Now your samples are inside the selected folder.
If you don't have iTunes, but have a router in your house.
1- Inside Reactable mobile, first go into Settings--> and turn the switch of "Web access" to on.
2- In your computer, put the same URL address that appears.
3- Upload the sounds (this has the disadvantage of having to select them one by one)
From here on follow the steps 2-5 of the process described in the previous section part, since you're already inside reactable.