CryptoPad

TL;DR: ridiculous protection for your irrelevant (and not irrelevant) data, literature, reminders, secrets, etc.

The app has no access to the internet.

Multiple pads can be created, each protected by its own password and unique key for decryption.

Works as follows:

Creation of pad:

1. The user creates a notepad and sets a password.

2. The password is hashed using a salt stored in an encrypted location which can only be accessed by a random key created by the app on its first run.

3. A unique key for the pad is generated and stored in the Keystore, keys stored here can't be retrieved as text, they can at most be used by the code.

Authentication:

1. User gives a password.

2. Password is hashed and used to access the pad's unique key stored in the Keystore.

3. The unique key is used for decrypting the stored files.

4. The decrypted notes are stored in memory until the user closes the app.

5. Notes are safely stored as files filled with apparent gibberish.

6. No one reads your stuff ever.

The future:

Options for exporting the decrypted files and importing them on a new device.

More themes.

Spell check.

Whatever people ask for.

Warnings:

Don't forget your password or lose your phone.