Emulatorn don't save in Android 4.0 in NAVCITY Tablet

[Android Question]

Hi, I downloaded some emulators for my tablet, but none of them can save save states in the actual emulator, and inside-game saves doesn't work as well. I tried to look for some help and the most I found was that I had to change the permissions of the folders where the games were, but I tried to do it with RootBrowser and it said that it was unable to complete the operation.

What can I do? I see some reviews of the emulators and everyone says that they save alright.

My Android Version is 4.0, and my tablet is a NAVCITY NT1710 (it's pretty bad, haha).
The emulators I tried to save were SuperGNES, GBA.emu, My Boy! and Nostalgia.nes.