Cheers guys,
does anyone know if Cryptomator stores my data itself during the process of encryption and while keeping data in the secure cloud directory?
Thank you 
I’m a cryptomator user.
Cryptomator is an app installed on your device that works locally. It doesn’t phone home to ask instructions and provide information, You can encrypt data on your local device to create a vault that can exist in encrypted (locked) or unencrypted (unlocked) form… only locally.
If you choose to store your vault on the cloud then the only thing that changes is the locked / encrypted vault is stored on the cloud and the app works through the oprating system to read/write encrypted data to/from that cloud account. The unencrypted / unlocked version only exists locally, it is never sent off device.
BTW the software is also open source so it would be very difficult for them to do something sneaky.
In short: No
Like @cryptwo said, Cryptomator encrypts only locally. Decryption is made on-the-fly, i.e. only when accessing an unlocked vault and the decrypted content is stored on volatile memory. The encryption is transparant, no data other than the files put into a vault are stored. Cryptomator does not require an internet connection or an account.
The mobile applications directly access your cloud storages and, hence, need to store the credentials for those. But also here, no other data is stored or sent anywhere.