Text Encryption

Text encryption can be useful for different purposes. There's the "easy hiding" of spoilers (e.g. using Caesar-Chiffre aka "ROT-13", also used with Geo-Caching), or Morse-Codes. And there are more serious things like safe-guarding sensitive information with real encryption. For all this, you can find matching Android apps:

Caesar-Cipher

2021-04-13

Caesar-Cipher is also known as "ROT" (from "rotate"), as the algorithm rotates the letters of the alphabet (e.g. 13 times with ROT-13), which is easily revertable. Caesar is said having used this to encrypt military correspondence, hence the name.

Rot13 ↺ Edg13 (5@4) 0 $Contains no trackers known to us \o/$ LastUpdate: 2017-03-15
CaesarCipher (5@1) 0 $Contains no trackers known to us \o/$
Caesar (4.9@8) 2 2 LastUpdate: 2018-01-13
ROT13 (4.6@34) 0 $Contains no trackers known to us \o/$
ROT13 Translator (4.3@90) 0 $Contains no trackers known to us \o/$ LastUpdate: 2014-07-20
Caesar cipher (4.3@13) 2 1 LastUpdate: 2013-02-26
Caesar Cipher Disk (4.2@178) 1 $Contains no trackers known to us \o/$
Caesar cipher - Encryption / automatic decryption (4.2@129) 2 $Contains no trackers known to us \o/$
Pijaret (0@0) 0 $Contains no trackers known to us \o/$ LastUpdate: 2016-09-27 Github

Morse Code

Morse code was used for telegraphy long ago. But it's still active in seafaring today (often as light signals), its best known example probably being the SOS distress signal.

Morse Tutors

2021-04-13

Morse Mania: Learn Morse Code (4.8@8,445) Ǥ 13 3
Morse Trainer for Ham Radio (4.6@345; ~EUR 3.25) 3 $Contains no trackers known to us \o/$ LastUpdate: 2018-01-06
Morse Mentor (4.4@261) 3 2
Morse Code Trainer (4.2@4,929) 1 $Contains no trackers known to us \o/$ LastUpdate: 2013-07-22
Morse App (Learn Morse code) (4.1@1,754) Ǥ 7 1 LastUpdate: 2014-11-27
Learn Morse Code - G0HYN Learn Morse (4.1@81) 2 $Contains no trackers known to us \o/$
Morse code - learn and play (4@664) 6 2 / Morse code - learn and play - Premium (4.4@119; ~EUR 2.00) 3 $Contains no trackers known to us \o/$
Mors. : The Morse Code Trainer (3.9@362) 2 1
Morse Audio - Morse Code Learn (3.8@40) Ǥ 3 1 LastUpdate: 2018-12-03
Morse Code Trainer & Learning Game - 2019 (2.3@9) 3 1 LastUpdate: 2019-05-14
MorseTrainer (0@0) 0 $Contains no trackers known to us \o/$ Github

General Morse apps

2021-04-13

BF4 Lantern & Morse Solver (4.7@1,028) 5 1
Morse Code Translator (4.5@77) 4 3
TwitMorse -Tweet morse code!- (4.5@17) Ǥ 4 4
Scout: Morse Translator (4.5@15) Ǥ 5 2 LastUpdate: 2019-08-21
Morse Code (4.4@6,164) 7 1
M³ Translator: Morse code (4.4@4,649) Ǥ 13 3
morsee : Enjoy Morse code (4.4@857) Ǥ 7 5
Morse Transmitter (4.3@1,089) 1 $Contains no trackers known to us \o/$ LastUpdate: 2014-01-20
Morse Torch (4.3@18) 2 $Contains no trackers known to us \o/$ LastUpdate: 2018-11-30
Pocket Talk (4.3@6) 5 $Contains no trackers known to us \o/$ LastUpdate: 2016-01-13
Morse Translator - Morse Code & Editable Alphabet (4.2@68) 7 2
Morse (4.1@1,660) 5 2 LastUpdate: 2018-03-10
Morse Code Translator (3.9@2,289) Ǥ 11 12
Morse Code Reader (3.9@1,777) 2 $Contains no trackers known to us \o/$ LastUpdate: 2013-08-27
Morse Code (3.9@379) 3 $Contains no trackers known to us \o/$
Morse From RSS News Feeds (3.9@7) 2 $Contains no trackers known to us \o/$
SMS-Morse (3.8@17) 0 $Contains no trackers known to us \o/$ LastUpdate: 2019-05-21
Morse (3.7@6) 2 $Contains no trackers known to us \o/$ Github
Morse Me (3.6@83) Ǥ 9 4
Morse Code Translator (3.4@35) 4 3 LastUpdate: 2017-02-15
Morse Decoder for Ham Radio (3.3@200; ~EUR 5.50) 6 $Contains no trackers known to us \o/$ LastUpdate: 2017-03-15

Morse Keyboards

2021-04-14

DotDash Keyboard (3.8@255) 1 $Contains no trackers known to us \o/$ Github
Morse Code Keyboard (3.8@111) Ǥ 5 3 LastUpdate: 2018-12-08
Morse Code Keyer (3.7@151) 5 1
MouseCode Keyboard (3.7@3) 1 $Contains no trackers known to us \o/$ LastUpdate: 2017-03-01
Morse Straight Key (3.3@198) 1 $Contains no trackers known to us \o/$ LastUpdate: 2014-06-28

Multiple text-encryption methods

2021-04-14

Cryptography Fun (5@5) 0 $Contains no trackers known to us \o/$ LastUpdate: 2016-04-09 Caesar, Vigenere, Affine, Matrix, R.S.A.
Cipher - Decipher (4.6@33) 2 2 LastUpdate: 2017-06-09 Caesar Cipher, Vigenere Cipher, Playfair Cipher …
Coooder - encode & encrypt (4.6@5) Ǥ 5 4 LastUpdate: 2019-02-09
Cryptography - Collection of ciphers and hashes (4.5@3,054) Ǥ 9 3
Ciphertext Tools - Classical Cryptography (4.5@11) 5 1
Cipher Decoder Cipher Solver (4.3@2,476) Ǥ 7 4 LastUpdate: 2019-05-15
Cipher Solver (4.3@186) 0 $Contains no trackers known to us \o/$ LastUpdate: 2016-11-10 Caesar, Vigenère …
Cipher Tool (4.3@18) 1 $Contains no trackers known to us \o/$
Cipher Sender (4.2@90) 3 1 LastUpdate: 2017-07-05 Caesar Shift, Morse Code, Rail Fence, Rot13, Monoalphabetic Substitution, Vigenere, Letter-Number Code, Atbash, Keyboard Code;
⭐Message/Text Encryptor - Secure Encryption.⭐ (4.2@25) 3 1 LastUpdate: 2019-05-02
Decrypto (4.1@3,619) 4 1 LastUpdate: 2017-09-30 / DecryptoPro (4.2@212; ~EUR 1.75) 5 $Contains no trackers known to us \o/$ LastUpdate: 2017-09-30
Cipher tools (4.1@837) 1 $Contains no trackers known to us \o/$ LastUpdate: 2012-05-09 vigenere, mobile cipher, morse code, ascii code, binary code, oct code, hex code, base64 code, digital sum, reverse words or text, ROT cipher, roman numbers, braille decoder, fake text, front to back text, mathias sandorf, playfair
Universal Encoding Tool (4@144) 0 $Contains no trackers known to us \o/$
Cryptography Tools - Ciphertext, Hashing, Encoding (4@16) 5 2
CryptoTool (3.9@15) Ǥ 7 1 LastUpdate: 2016-11-08
Cryptography Mean™ - Encryption, decryption tools (3.7@3) Ǥ 5 1 LastUpdate: 2018-07-24
Encrypt Decrypt Tools (3.6@281) 4 3

Text encryption with PGP

2021-04-14

Latebra cryptographic app (4.6@8) Ǥ 21 4 encrypt SMS/Email
Tessercube (4.4@23) 20 $Contains no trackers known to us \o/$ Github
APG (4.2@13) 6 $Contains no trackers known to us \o/$ LastUpdate: 2014-04-04 Github; Description and Howto; Wikipedia (EN); Files + Mails
OpenKeychain: Easy PGP (4.1@3,528) Ǥ 13 $Contains no trackers known to us \o/$ Github; Kurzvorstellung 7/2015; Video Howto 9/2016 (DE); Howto 12/2017 | 2/2019; Wikipedia DE | EN
PGPClipper (4.1@11) 3 $Contains no trackers known to us \o/$ LastUpdate: 2018-12-12 Github
PGP SMS lite (3.9@156) 8 $Contains no trackers known to us \o/$ LastUpdate: 2016-05-30
PGPTools (3.5@114; ~EUR 1.00) 3 $Contains no trackers known to us \o/$ LastUpdate: 2017-11-14 / PGPFiles (2.6@19; ~EUR 1.00) 3 $Contains no trackers known to us \o/$ LastUpdate: 2017-04-25
PGP KeyRing (Trial Version) (2.8@38) 5 $Contains no trackers known to us \o/$ LastUpdate: 2018-10-31 maintain your PGP keyrings
OkcAgent (0@0; ~EUR 1.00) 3 $Contains no trackers known to us \o/$ Github; make OpenKeychain available in your Termux shell

Encryption with AES/DES

2021-04-14

Notepad with password FREE (4.7@3,414) Ǥ 7 2 / Notepad with password PRO (4.3@80; ~EUR 3.00) 2 $Contains no trackers known to us \o/$
Encrypt It - MkII (4.6@38) $Contains no trackers known to us \o/$ LastUpdate: 2014-05-14
Private Notepad - safe notes & lists (4.5@39,252) Ǥ 14 5
SSE - File/Text Encryption & Password Vault (4.4@3,225) Ǥ 5 $Contains no trackers known to us \o/$ Password-Safe, texts, files, and more; cross-platform (Windows, Linux, Mac OS X, …); Open Source
Encrypt text with CryptMax (4.4@75) 2 1 LastUpdate: 2017-01-18
AES Message Encryptor for SMS (4.3@134) 0 $Contains no trackers known to us \o/$ LastUpdate: 2017-01-15
SealNote Secure Encrypted Note (4.2@3,116) 2 $Contains no trackers known to us \o/$ LastUpdate: 2017-04-13 Github; Video Intro 4/2017
Cryptool (4.1@124) 1 $Contains no trackers known to us \o/$ Github
AES Encryption App FREE (4@44) 2 $Contains no trackers known to us \o/$ / AES Encryption App Pro (4.6@12; ~EUR 0.75) 0 $Contains no trackers known to us \o/$ LastUpdate: 2014-06-20
Sec Notes- Free Secure Notepad (3.9@1,329) Ǥ 12 3
CrocodileNote (3.6@16) 2 $Contains no trackers known to us \o/$ LastUpdate: 2015-03-13 Github; AES-256 encrypted notes
SimpleTextCrypt (0@0) 0 $Contains no trackers known to us \o/$ Github
Encrypt Text (0@0) 0 $Contains no trackers known to us \o/$ Github

Various other encryption apps

2021-04-14

Enigma Simulator (4.6@2,101) Ǥ 3 $Contains no trackers known to us \o/$ LastUpdate: 2017-07-14
Crypto - Tools for Encryption & Cryptography (4.6@1,004) Ǥ 12 3
Cryptogram (4.6@819) 0 $Contains no trackers known to us \o/$ LastUpdate: 2012-05-31
Latebra cryptographic app (4.6@8) Ǥ 21 4 encrypt SMS/Email
TXTcrypt (4.4@79) $Contains no trackers known to us \o/$ LastUpdate: 2016-06-28
Cryptogram Puzzle Quotes Game (4.3@1,496) Ǥ 5 3
Safe Notes is a secure notepad (4.2@5,211) 11 4
Kryptomat (4.2@28) 2 $Contains no trackers known to us \o/$
SEED Encryption App Free (4.2@18) 2 $Contains no trackers known to us \o/$ LastUpdate: 2014-06-20 / SEED Encryption App PRO (4@1; ~EUR 0.75) 0 $Contains no trackers known to us \o/$ LastUpdate: 2014-06-20
PGPClipper (4.1@11) 3 $Contains no trackers known to us \o/$ LastUpdate: 2018-12-12 Github
Oversec (4@255) Ǥ 4 $Contains no trackers known to us \o/$ LastUpdate: 2019-04-23
Crypto - RSA encryption by Cronkhinator (4@22) 1 $Contains no trackers known to us \o/$ LastUpdate: 2019-04-14
Enigma Trial - Cryptograms (3.5@182) 0 $Contains no trackers known to us \o/$ LastUpdate: 2017-12-09 / Enigma - Cryptograms (4.4@169; ~EUR 1.00) 0 $Contains no trackers known to us \o/$ LastUpdate: 2017-12-09
Encrypt Editor (3.1@35) 5 2
PixelKnot: Hidden Messages (2.6@1,144) 4 $Contains no trackers known to us \o/$ LastUpdate: 2017-02-26 Github; Details; Steganography (text hidden inside image, unlock with passphrase)
EnigmAndroid (0@0) 0 $Contains no trackers known to us \o/$ LastUpdate: 2019-01-03 Github; Enigma Simulation

Further Readings:

Category Encryption of Files and Folders
Category Messenger & Conferences

2021-04-14

IzzyOnDroid