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

2020-01-17

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 $Contains no known trackers \o/$ LastUpdate: 2017-03-15
CaesarCipher (5@1) 0 $Contains no known trackers \o/$
Caesar (4.9@8) 2 LastUpdate: 2018-01-13
ROT13 (4.6@21) 0 $Contains no known trackers \o/$ LastUpdate: 2013-12-24
Caesar cipher - Encryption / automatic decryption (4.5@50) 2 $Contains no known trackers \o/$
Caesar Cipher Disk (4.3@154) 3 $Contains no known trackers \o/$
ROT13 Translator (4.3@86) 0 $Contains no known trackers \o/$ LastUpdate: 2014-07-20
Caesar cipher (4.3@13) 2 LastUpdate: 2013-02-26
Caesar Cipher - Encrypt and decrypt messages (3.7@3) 2 LastUpdate: 2018-02-17
Pijaret (0@0) 0 $Contains no known trackers \o/$ 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

2020-01-17

Morse Trainer for Ham Radio (4.7@304; ~EUR 3.25) 3 LastUpdate: 2018-01-06
Morse Mania (4.7@285) Ǥ 5
Morse code - learn and play (4.4@291) 5 / Morse code - learn and play - Premium (4.7@56; ~EUR 2.00) 3
Morse Code Trainer (4.2@4,929) 1 $Contains no known trackers \o/$ LastUpdate: 2013-07-22
Morse App (Learn Morse code) (4.1@1,754) Ǥ 7 LastUpdate: 2014-11-27
Morse Mentor (4.1@228) 3
Learn Morse Code - G0HYN Learn Morse (4.1@61) 2 $Contains no known trackers \o/$
Mors. : The Morse Code Trainer (3.8@309) 2
Morse Audio - Morse Code Learn (3.8@38) Ǥ 3 $Contains no known trackers \o/$ LastUpdate: 2015-01-30
Morse Code Trainer & Learning Game - 2019 (2.3@6) 3

General Morse apps

2020-01-17

Scout: Morse Translator (5@13) Ǥ 5
BF4 Lantern & Morse Solver (4.8@821) 5 LastUpdate: 2017-05-30
Morse Code Translator (4.7@74) 2
Morse Code (4.6@4,228) 7
TwitMorse -Tweet morse code!- (4.6@16) Ǥ 4
SMS-Morse (4.5@10) 0 $Contains no known trackers \o/$
M³ Translator: Morse code (4.4@3,264) Ǥ 12
Morse Code Translator (4.3@1,725) Ǥ 11
Morse Transmitter (4.3@1,062) 1 $Contains no known trackers \o/$ LastUpdate: 2012-10-16
morsee : Enjoy Morse code (4.3@411) Ǥ 6
Morse Translator - Morse Code & Editable Alphabet (4.3@48) 7
Morse Torch (4.3@18) 2 $Contains no known trackers \o/$
Pocket Talk (4.3@6) 4 LastUpdate: 2016-01-13
Morse (4@1,440) 5 LastUpdate: 2018-01-26
Morse Code Translator (4@1,262) 4 LastUpdate: 2017-02-15
Morse Code (4@380) 3 $Contains no known trackers \o/$ LastUpdate: 2014-08-04
Morse Me (3.8@74) Ǥ 7
Morse Code Reader (3.7@1,592) 2 $Contains no known trackers \o/$ LastUpdate: 2013-08-27
Morse From RSS News Feeds (3.7@6) 2 $Contains no known trackers \o/$ LastUpdate: 2017-12-13
Morse Decoder for Ham Radio (3.5@177; ~EUR 5.50) 6 LastUpdate: 2017-03-15
Hue Morse (3.5@4) 1 $Contains no known trackers \o/$ LastUpdate: 2017-10-13 morse via Philips Hue lights
Morse (2@1) 2 Github
Morse Converter (0@0) Ǥ 5

Morse Keyboards

2020-01-17

Morse Code Keyboard (3.9@58) Ǥ 5 LastUpdate: 2017-04-20
DotDash Keyboard (3.8@229) 1 $Contains no known trackers \o/$ LastUpdate: 2015-12-14 Github
MouseCode Keyboard (3.7@3) 1 $Contains no known trackers \o/$ LastUpdate: 2017-03-01
Morse Straight Key (3.5@192) 1 $Contains no known trackers \o/$ LastUpdate: 2014-06-28
Morse Code Keyer (3.5@117) 4

Multiple text-encryption methods

2020-01-17

Cryptography Fun (5@5) 0 $Contains no known trackers \o/$ LastUpdate: 2016-04-09 Caesar, Vigenere, Affine, Matrix, R.S.A.
Coooder - encode & encrypt (5@1) Ǥ 5
Cryptography - Collection of ciphers and hashes (4.6@2,696) Ǥ 8
Cipher - Decipher (4.6@33) 2 LastUpdate: 2017-06-09 Caesar Cipher, Vigenere Cipher, Playfair Cipher …
Cipher Tool (4.6@9) 0 $Contains no known trackers \o/$
Cipher Tools (4.5@8) 2 LastUpdate: 2018-06-21
Cipher Solver (4.4@166) 0 $Contains no known trackers \o/$ LastUpdate: 2016-11-10 Caesar, Vigenère …
⭐Message/Text Encryptor - Secure Encryption.⭐ (4.4@12) 3
Decrypto (4.3@3,058) 4 LastUpdate: 2017-09-30 / DecryptoPro (4.5@170; ~EUR 1.75) 5 LastUpdate: 2017-09-30
Cipher tools (4.3@814) 1 $Contains no known trackers \o/$ 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
Cipher Sender (4.2@90) 3 LastUpdate: 2017-07-05 Caesar Shift, Morse Code, Rail Fence, Rot13, Monoalphabetic Substitution, Vigenere, Letter-Number Code, Atbash, Keyboard Code;
Cipher Decoder Cipher Solver (4@2,172) Ǥ 7
Universal Encoding Tool (4@145) 0 $Contains no known trackers \o/$
CryptoTool (3.9@15) Ǥ 7 LastUpdate: 2016-11-08
Encrypt Decrypt Tools (3.7@254) 2
Cryptography Mean™ - Encryption, decryption tools (3.7@3) Ǥ 5
Cryptography Tools (3.6@11) 2

Text encryption with PGP

2020-01-18

Latebra cryptographic app (4.5@6) Ǥ 21 encrypt SMS/Email
OpenKeychain: Easy PGP (4.2@2,819) Ǥ 20 Github; Kurzvorstellung 7/2015; Video Howto 9/2016 (DE); Howto 2/2019; Wikipedia DE | EN
APG (4.2@13) 5 LastUpdate: 2014-04-04 Description and Howto; Wikipedia (EN); Files + Mails
p≡p pretty Easy privacy (4.1@50) 13 LastUpdate: 2018-01-27 / pretty Easy privacy p≡p (3.6@106; ~EUR 0.50) 15 PGP encrypted email; Testbericht 6/2018
PGPClipper (4.1@11) 3 Github
PGP SMS lite (3.9@156) 8 $Contains no known trackers \o/$ LastUpdate: 2016-05-30
PGPTools (3.7@98; ~EUR 1.00) 3 LastUpdate: 2017-11-14 / PGPFiles (2.9@16; ~EUR 1.00) 3 LastUpdate: 2017-04-25
PGP KeyRing (Trial Version) (2.9@37) 5 $Contains no known trackers \o/$ / PGP KeyRing (3.6@56; ~EUR 3.00) 6 maintain your PGP keyrings

Encryption with AES/DES

2020-01-18

DCipher (4.7@6) 2 $Contains no known trackers \o/$ Github
Notepad with password FREE (4.6@3,020) Ǥ 6 / Notepad with password PRO (4.2@69; ~EUR 3.00) 2
SSE - File/Text Encryption & Password Vault (4.6@2,757) Ǥ 4 $Contains no known trackers \o/$ Intro 2/2013; Password-Safe, texts, files, and more; cross-platform (Windows, Linux, Mac OS X, …); Open Source
Encrypt It - MkII (4.6@36) 0 $Contains no known trackers \o/$ LastUpdate: 2014-05-14
Private Notepad - safe notes & lists (4.5@33,673) Ǥ 14
Cryptool (4.5@69) 1 $Contains no known trackers \o/$ Github
AES Message Encryptor for SMS (4.4@123) 0 $Contains no known trackers \o/$ LastUpdate: 2017-01-15
Encrypt text with CryptMax (4.4@75) 2 LastUpdate: 2017-01-18
SealNote Secure Encrypted Note (4.3@2,978) 2 $Contains no known trackers \o/$ LastUpdate: 2017-04-13 Github; Video Intro 4/2017
Sec Notes- Free Secure Notepad (4.3@1,087) Ǥ 10 LastUpdate: 2018-05-23
DES Encryption (4.2@6) 0 $Contains no known trackers \o/$ LastUpdate: 2015-01-29
AES Encryption App FREE (4.1@41) 2 $Contains no known trackers \o/$ LastUpdate: 2014-06-20 / AES Encryption App Pro (4.9@7; ~EUR 0.75) 0 $Contains no known trackers \o/$ LastUpdate: 2014-06-20
Secure notes - Notepad (4.1@21) Ǥ 14 LastUpdate: 2018-06-13
CrocodileNote (3.6@13) 2 $Contains no known trackers \o/$ LastUpdate: 2015-03-13 Github; AES-256 encrypted notes
Encrypt It (3.5@124) 0 $Contains no known trackers \o/$ LastUpdate: 2013-08-22
SimpleTextCrypt (0@0) 0 $Contains no known trackers \o/$ LastUpdate: 2015-12-29 Github
Encrypt Text (0@0) 0 $Contains no known trackers \o/$ LastUpdate: 2018-06-02 Github

Messenger with encryption

2020-01-06

Threema (4.6@59,042; ~EUR 4.00) Ǥ 26 / Threema QR Scanner Plugin (4.5@7,873) 1 $Contains no known trackers \o/$ LastUpdate: 2018-03-06 Video Review 12/2013 (EN) | 4/2016 (DE) | 3/2019 (DE); Video Backup & Restore (3/2019); Video Threema Webchat Howto 2/2017 (DE); Threema Video Tutorials; Test 4/2016; Vorstellung 2/2014 | 2/2014 | 2/2014 | 8/2018 | 11/2018; Wikipedia DE|EN; Audit 11/2015 | 3/2019; Tipps & Tricks 12/2015; Anrufe 9/2017; Backup Tipps 10/2017; FAQ; messenger with end-to-end encryption
Quicksy (4.6@55) Ǥ 21 Github; Vorstellung 11/2018; fork of Conversations using your phone number as ID
Telegram (4.5@4,455,648) Ǥ 39 Github; Testbericht 10/2013 | 7/2016; Meldung 4/2014; Vorstellung 5/2014 | 8/2018-6/2019; Security Analysis 5/2017; Video Erklärung 7/2019; Wikipedia DE|EN; encryption and self-destruct timer
Signal Private Messenger (4.5@393,684) Ǥ 49 $Contains no known trackers \o/$ Testbericht 11/2013; Vorstellung 11/2015 | 11/2015 | 11/2015 | 8/2018; "Crypto-SMS" und verschlüsselte Telefonie (ehemals TextSecure + RedPhone) | 11/2015
whispeer Messenger (4.5@30) Ǥ 16 Github; DerStart 8/2015; FU-Berlin 5/2017
VIPole Private Messenger (4.4@10,276) Ǥ 19 also available for Windows, Linux and Mac OS, paid subscription needed for end-to-end encryption
surespot encrypted messenger (4.4@3,110) Ǥ 11 Github; Vorstellung 2/2014; Wikipedia DE|EN; send encrypted messages. unlock voice messages per in-app payment. AES end-to-end encryption.
Conversations (Jabber / XMPP) (4.4@1,675; ~EUR 2.50) Ǥ 21 / Conversations Legacy (4.1@152) 14 $Contains no known trackers \o/$ / Share Location Plugin (4.6@66) Ǥ 7 $Contains no known trackers \o/$ LastUpdate: 2017-12-28 / Voice Recorder Plugin (4.2@58) 3 $Contains no known trackers \o/$ LastUpdate: 2016-11-13 Github; XMPP/Jabber; PGP/OTR/OMEMO; Wikipedia DE | EN; Vorstellung & Schnelleinstieg 5/2016; Anleitung für Anfänger 7/2018
mini Vector (4.4@17) Ǥ 14 Github; riot client; see here for privacy issues with the Matrix/riot network
TigerConnect - Clinical Solutions (4.3@5,021) Ǥ 29
Pix-Art Messenger (XMPP / Jabber Client) (4.3@109) Ǥ 25 Github; fork of Conversations
Wickr Me – Private Messenger (4.1@19,026) Ǥ 19 Vorstellung 9/2013; Intro 9/2013; Wikipedia EN; end-to-end encryption with mission-impossible-flair (self-destructing messages)
Xabber (4.1@11,928) Ǥ 11 / Xabber (4.5@734) 8 LastUpdate: 2017-05-15 Github; Vorstellung 11/2013; Testbericht 8/2013 / Github
Kontalk Messenger (4.1@590) Ǥ 32 Github; Vorstellung 8/2018
ginlo (SIMSme Private) (4@15,932) Ǥ 18 Vorstellung 9/2018
Briar (4@472) 15 / Briar Beta (Unreleased) (0@0) 9 LastUpdate: 2018-04-25 Video Intro 7/2017; Video Review 7/2018; Vorstellung 9/2018 / Kurzvorstellung 2/2018; Source & Issues
Zom Mobile Messenger (4@226) 22 Github; Intro 10/2015; XMPP; multi-platform; fork of ChatSecure; note: no longer developed/maintained
Skriva - Secure communication made simple (4@2) Ǥ 15 $Contains no known trackers \o/$ Github; Fork of Conversations
Nextcloud Talk (3.9@482) Ǥ 22 Github
aTalk (Jabber / XMPP) (3.9@54) 22 Github
Secure MMX Encrypted Messenger (3.9@28) Ǥ 14 $Contains no known trackers \o/$ LastUpdate: 2016-11-20
[Old] Riot.im (3.8@1,302) Ǥ 28 / RiotX - Next Generation Matrix Client (0@0) 13 Github; Kurzvorstellung 12/2016 / Github
Wire • Secure Messenger (3.6@31,338) Ǥ 16 Testberichte 4/2017; Privacy-Warnung 7/2018; Vorstellung 8/2018 - 11/2019; free/gratis, encrypted communication: voice, video and group chats; cross platform: Android, iOS, Mac, Windows. Or in the web browser.
Chiffry Secure Messenger (3.1@860) Ǥ 22
Hoccer – the secure Messenger (2.9@7,995) Ǥ 14 Vorstellung 8/2018
Rocket.Chat (2.6@2,113) Ǥ 17 Github; chat with screen and file sharing, and more
Delta Chat (0@0) 20 Github; Vorstellung 6/2019
Conv6ations for Sum7 (0@0) 20 $Contains no known trackers \o/$ fork of Conversations
Pattle (0@0) 3 client for riot/Matrix
Dib2Qm (0@0) 8 $Contains no known trackers \o/$ GitLab; based on IMAP and QuickMSG (no centralized server)

Various other encryption apps

2020-01-17

Cryptogram (4.8@803) 0 $Contains no known trackers \o/$ LastUpdate: 2012-05-31
Enigma Simulator (4.7@1,961) Ǥ 3 $Contains no known trackers \o/$ LastUpdate: 2017-07-14
Latebra cryptographic app (4.5@6) Ǥ 21 encrypt SMS/Email
Cryptogram Puzzle Quotes Game (4.4@1,446) Ǥ 5 LastUpdate: 2018-01-19
Crypto - Tools for Encryption & Cryptography (4.4@318) Ǥ 12
TXTcrypt (4.4@79) 0 $Contains no known trackers \o/$ LastUpdate: 2016-06-28
Kryptomat (4.3@26) 2 $Contains no known trackers \o/$ LastUpdate: 2014-08-14
Oversec (4.2@187) Ǥ 4 $Contains no known trackers \o/$
SEED Encryption App Free (4.2@18) 2 $Contains no known trackers \o/$ LastUpdate: 2014-06-20 / SEED Encryption App PRO (4@1; ~EUR 0.75) 0 $Contains no known trackers \o/$ LastUpdate: 2014-06-20
Safe Notes is a secure notepad (4.1@5,152) 6
Crypto - RSA encryption by Cronkhinator (4.1@15) 1 $Contains no known trackers \o/$
PGPClipper (4.1@11) 3 Github
Enigma Trial - Cryptograms (3.2@182) 0 $Contains no known trackers \o/$ LastUpdate: 2017-12-09 / Enigma - Cryptograms (4.4@164; ~EUR 1.00) 0 $Contains no known trackers \o/$ LastUpdate: 2017-12-09
Encrypt Editor (3.2@33) 5
PixelKnot (2.8@1,057) 3 $Contains no known trackers \o/$ LastUpdate: 2017-02-19 Github; Details; Steganography (text hidden inside image, unlock with passphrase)
EnigmAndroid (0@0) 0 $Contains no known trackers \o/$ Github; Enigma Simulation

Further Readings:

Category Encryption of Files and Folders
Verschlüsselte Messenger: Threema, Signal, Telegram, WhatsApp (11-2015 - 6/2019)
Wire, Hoccer, Kontalk (9/2017)

2020-01-18

IzzyOnDroid