In this case if you stored your private key on your hard drive it will be possible to restore it if you did not deleted it properly.
Unless you use
whole disk encryption, which is supported out of the box by all major modern operating systems without the need for third-party utilities or funky bootloaders. There's no excuse for leaving data unencrypted in this day and age.
Hmm, seems nice.
As I understand it might encrypt not only the entire disc but also some separate files.
Immediate data destruction, such as simply destroying the cryptographic keys (crypto-shredding), renders the contained data useless. However, if security towards future attacks is a concern, purging or physical destruction is advised.
So in this case is there any chance to restore deleted encrypted files?
And what should I do with files that already were deleted?
P.S. I also need the same kind of app for my android and will appreciate your advice.
My question to you is, Why bother? Now that you have learned to make encrypted partitions from now on, you should just discard all your old wallets, make new ones and transfer everything there.
CCleaner and such are a pure waste of time, you should have never used windows in the first place.
And don't try those things in anything that is not a spinning magnetic drive, you will ruin it (unless that's what you want); and i don't mean the data, the storage device (flash / nand).