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

2022-05-19

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 $Contains no trackers known to us \o/$ LastUpdate: 2019-10-22
Caesar Cipher Disk (4.8@181) 1 $Contains no trackers known to us \o/$
ROT13 Translator (4.8@99) 0 $Contains no trackers known to us \o/$ LastUpdate: 2014-07-20
Caesar cipher - Encryption / automatic decryption (4.7@171) 2 $Contains no trackers known to us \o/$ LastUpdate: 2020-04-15
ROT13 (4.7@50) 0 $Contains no trackers known to us \o/$
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

2022-05-19

Morse Mania: Learn Morse Code (4.8@15,416) Ǥ 13 2
Morse Trainer for Ham Radio (4.8@370; ~EUR 3.25) 3 $Contains no trackers known to us \o/$ LastUpdate: 2018-01-06
Learn Morse Code - G0HYN Learn Morse (4.4@92) 2 $Contains no trackers known to us \o/$ LastUpdate: 2020-02-26
Morse Mentor (4.3@287) 4 2
Morse code - learn and play (4.1@725) 6 2 LastUpdate: 2020-06-05 / Morse code - learn and play - Premium (4.9@134; ~EUR 2.00) 3 $Contains no trackers known to us \o/$ LastUpdate: 2019-12-17
Mors. : The Morse Code Trainer (3.3@379) 2 1 LastUpdate: 2020-06-15
Morse Code Trainer & Learning Game - 2019 (2.3@10) 3 1 LastUpdate: 2019-05-14
Morse Audio - Morse Code Learn (1@42) Ǥ 3 1 LastUpdate: 2018-12-03
MorseTrainer (0@0) 0 $Contains no trackers known to us \o/$ Github

General Morse apps

2022-05-19

Morse Code Translator (5@93) 4 1
Morse Translator - Morse Code & Editable Alphabet (5@73) 7 2 LastUpdate: 2020-02-04
Morse (5@8) 2 $Contains no trackers known to us \o/$ Github
BF4 Lantern & Morse Solver (4.7@1,201) 5 1 LastUpdate: 2020-07-21
Morse Torch (4.5@17) 2 $Contains no trackers known to us \o/$ LastUpdate: 2018-11-30
TwitMorse -Tweet morse code!- (4.5@17) Ǥ 4 4 LastUpdate: 2020-10-21
Scout: Morse Translator (4.5@15) Ǥ 6 2
Morse Code (4.4@7,248) 7 1 LastUpdate: 2020-03-17
M³ Translator: Morse code (4.3@5,136) Ǥ 13 3
Pocket Talk (4.3@6) 5 $Contains no trackers known to us \o/$ LastUpdate: 2016-01-13
morsee : Enjoy Morse code (4@1,083) Ǥ 7 4
Morse Code (4@379) 3 $Contains no trackers known to us \o/$ LastUpdate: 2020-04-15
Morse Code Reader (3.9@1,909) 2 $Contains no trackers known to us \o/$ LastUpdate: 2013-08-27
Morse Transmitter (3.8@1,093) 1 $Contains no trackers known to us \o/$ LastUpdate: 2014-01-20
Morse (3.7@1,748) 5 2 LastUpdate: 2018-03-10
Morse Code Translator (3.6@2,529) Ǥ 11 3
Morse Me (3.5@87) Ǥ 9 4 LastUpdate: 2020-05-28
Morse Code Translator (3.4@1,257) 4 3 LastUpdate: 2017-02-15
Morse Decoder for Ham Radio (3.3@208; ~EUR 5.50) 6 $Contains no trackers known to us \o/$ LastUpdate: 2017-03-15
SMS-Morse (1@20) 0 $Contains no trackers known to us \o/$

Morse Keyboards

2022-05-19

DotDash Keyboard (4.4@276) 1 $Contains no trackers known to us \o/$ LastUpdate: 2020-05-20 Github
Morse Code Keyer (4@167) 5 1 LastUpdate: 2020-02-23
MouseCode Keyboard (3.7@3) 1 $Contains no trackers known to us \o/$ LastUpdate: 2017-03-01
Morse Code Keyboard (3@141) Ǥ 5 3 LastUpdate: 2018-12-08

Multiple text-encryption methods

2022-05-19

Cipher tools (4.6@838) 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
Coooder - encode & encrypt (4.6@5) Ǥ 5 4 LastUpdate: 2019-02-09
Cipher Decoder Cipher Solver (4.5@2,607) Ǥ 7 4 LastUpdate: 2019-05-15
Cryptography - Collection of ciphers and hashes (4.4@3,223) Ǥ 9 3
Decrypto (4.3@3,882) 4 1 LastUpdate: 2017-09-30 / DecryptoPro (4.5@233; ~EUR 1.75) 5 $Contains no trackers known to us \o/$ LastUpdate: 2017-09-30
Cipher Solver (4.2@188) 0 $Contains no trackers known to us \o/$ LastUpdate: 2016-11-10 Caesar, Vigenère …
Universal Encoding Tool (4.2@146) 0 $Contains no trackers known to us \o/$ LastUpdate: 2020-02-05
Cipher Tool (4.2@20) 1 $Contains no trackers known to us \o/$ LastUpdate: 2020-08-06
⭐Message/Text Encryptor - Secure Encryption.⭐ (4@28) 3 1 LastUpdate: 2019-05-02
Cryptography Mean™ - Encryption, decryption tools (1@5) Ǥ 5 1 LastUpdate: 2018-07-24

Text encryption with PGP

2022-05-19

Latebra cryptographic app (4.6@8) Ǥ 21 4 encrypt SMS/Email
APG (4.2@13) 6 $Contains no trackers known to us \o/$ LastUpdate: 2014-04-04 Github; Description and Howto; Wikipedia (EN); Files + Mails
PGPClipper (4.1@11) 3 $Contains no trackers known to us \o/$ LastUpdate: 2018-12-12 Github
OpenKeychain: Easy PGP (4@3,820) Ǥ 13 $Contains no trackers known to us \o/$ Github; Kurzvorstellung 7/2015; Video Howto 9/2016 (DE); Howto 12/2017 | 2/2019; Anleitung 8/2020 | 11/2020; Wikipedia DE | EN
YAP! - Yet Another PGP Tool (3.9@61) 2 $Contains no trackers known to us \o/$ Github
PGPTools (3@116; ~EUR 1.00) 3 $Contains no trackers known to us \o/$ LastUpdate: 2017-11-14
Tessercube (1@30) 20 $Contains no trackers known to us \o/$ LastUpdate: 2020-07-25 Github
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

2022-05-19

AES Message Encryptor for SMS (5@137) 0 $Contains no trackers known to us \o/$ LastUpdate: 2017-01-15
Cryptool (4.6@157) 1 $Contains no trackers known to us \o/$ LastUpdate: 2020-04-06 Github
Sec Notes- Free Secure Notepad (4.4@1,429) Ǥ 12 2
Private Notepad - safe notes (4.3@44,775) Ǥ 18 5
Notepad with password (4.3@3,617) Ǥ 9 4 / Notepad with password PRO (4.3@87; ~EUR 3.75) 2 $Contains no trackers known to us \o/$ LastUpdate: 2019-10-26
SSE - File/Text Encryption & Password Vault (4.3@3,488) Ǥ 6 $Contains no trackers known to us \o/$ Password-Safe, texts, files, and more; cross-platform (Windows, Linux, Mac OS X, …); Open Source
SealNote (4.3@3,157) 2 $Contains no trackers known to us \o/$ LastUpdate: 2017-04-13 Github; Video Intro 4/2017
CrocodileNote (3.5@16) 2 $Contains no trackers known to us \o/$ LastUpdate: 2015-03-13 Github; AES-256 encrypted notes
SimpleTextCrypt (0@0) 0 $Contains no trackers known to us \o/$ LastUpdate: 2020-10-10 Github
Encrypt Text (0@0) 0 $Contains no trackers known to us \o/$ LastUpdate: 2020-08-23 Github

Various other encryption apps

2022-05-19

Cryptogram (4.8@834) 0 $Contains no trackers known to us \o/$ LastUpdate: 2012-05-31
Latebra cryptographic app (4.6@8) Ǥ 21 4 encrypt SMS/Email
Enigma Simulator (4.5@2,159) Ǥ 3 $Contains no trackers known to us \o/$ LastUpdate: 2017-07-14
Crypto - Tools for Encryption & Cryptography (4.5@1,411) Ǥ 11 3
Enigma Trial - Cryptograms (4.3@182) 0 $Contains no trackers known to us \o/$ LastUpdate: 2017-12-09 / Enigma - Cryptograms (5@169; ~EUR 1.00) 0 $Contains no trackers known to us \o/$ LastUpdate: 2017-12-09
Safe Notes is a secure notepad (4.1@5,248) 11 4 LastUpdate: 2020-03-22
PGPClipper (4.1@11) 3 $Contains no trackers known to us \o/$ LastUpdate: 2018-12-12 Github
Cryptogram Puzzle Quotes Game (4@1,507) Ǥ 5 3 LastUpdate: 2020-04-26
Oversec (4@255) Ǥ 4 $Contains no trackers known to us \o/$ LastUpdate: 2019-04-23
Kryptomat (3.9@27) 2 $Contains no trackers known to us \o/$
PixelKnot: Hidden Messages (3.3@1,181) 4 $Contains no trackers known to us \o/$ LastUpdate: 2017-02-26 Github; Details; Steganography (text hidden inside image, unlock with passphrase)
Encrypt Editor (1@35) 5 2
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

2022-05-24

IzzyOnDroid