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

2019-08-08

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
Caesar cipher - Encryption / automatic decryption (4.6@34) 2 $Contains no known trackers \o/$
ROT13 (4.6@20) 0 $Contains no known trackers \o/$ LastUpdate: 2013-12-24
Caesar Cipher Disk (4.4@141) 3 $Contains no known trackers \o/$
ROT13 Translator (4.3@83) 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
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

2019-08-08

Morse Mania (5@11) Ǥ 5
Morse Trainer for Ham Radio (4.6@299; ~EUR 3.25) 3 LastUpdate: 2018-01-06
Morse Mentor (4.3@216) 3
Morse code - learn and play (4.3@163) 5 / Morse code - learn and play - Premium (4.8@11; ~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
Learn Morse Code - G0HYN Learn Morse (4@52) 2 $Contains no known trackers \o/$
Mors. : The Morse Code Trainer (3.9@273) 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 (2.6@5) 3

General Morse apps

2019-08-08

Scout: Morse (5@7) Ǥ 4
BF4 Lantern & Morse Solver (4.8@766) 5 LastUpdate: 2017-05-30
Morse Code (4.7@3,737) 7
Morse Code Translator (4.7@73) 2
Morse Torch (4.7@18) 2 $Contains no known trackers \o/$
M³ Translator: Morse code (4.6@3,002) Ǥ 12
TwitMorse -Tweet morse code!- (4.5@14) Ǥ 4
morsee : Enjoy Morse code (4.4@375) Ǥ 6
SMS-Morse (4.4@9) 0 $Contains no known trackers \o/$
Morse Code Translator (4.3@1,615) Ǥ 11
Morse Translator - Morse Code & Editable Alphabet (4.3@45) 7
Pocket Talk (4.3@6) 4 LastUpdate: 2016-01-13
Morse (4.2@1,359) 5 LastUpdate: 2018-01-26
Morse Code Translator (4.1@1,266) 4 LastUpdate: 2017-02-15
Morse Code Reader (3.9@1,541) 2 $Contains no known trackers \o/$ LastUpdate: 2013-08-27
Morse Transmitter (3.9@1,053) 1 $Contains no known trackers \o/$ LastUpdate: 2012-10-16
Morse Code (3.9@379) 3 $Contains no known trackers \o/$ LastUpdate: 2014-08-04
Morse Me (3.9@72) Ǥ 7
Morse From RSS News Feeds (3.8@4) 2 $Contains no known trackers \o/$ LastUpdate: 2017-12-13
Morse Decoder for Ham Radio (3.6@175; ~EUR 5.00) 6 LastUpdate: 2017-03-15
Morse Talk (3.5@764) 4 $Contains no known trackers \o/$ LastUpdate: 2012-11-18
Hue Morse (3.5@4) 1 $Contains no known trackers \o/$ LastUpdate: 2017-10-13 morse via Philips Hue lights
Morse (2@1) 0 Github
Morse Converter (0@0) Ǥ 5

Morse Keyboards

2019-08-08

DotDash Keyboard (4@222) 1 $Contains no known trackers \o/$ LastUpdate: 2015-12-14 Github
Morse Code Keyboard (3.9@51) Ǥ 5 LastUpdate: 2017-04-20
MouseCode Keyboard (3.7@3) 1 $Contains no known trackers \o/$ LastUpdate: 2017-03-01
Morse Code Keyer (3.6@117) 4 LastUpdate: 2014-06-28
Morse Straight Key (3.4@185) 1 $Contains no known trackers \o/$ LastUpdate: 2014-06-28

Multiple text-encryption methods

2019-08-08

Cipher Tool (5@8) 0 $Contains no known trackers \o/$
Cryptography Fun (5@5) 0 $Contains no known trackers \o/$ LastUpdate: 2016-04-09 Caesar, Vigenere, Affine, Matrix, R.S.A.
Cryptography Tools (5@4) 2
Coooder - encode & encrypt (5@1) Ǥ 5
Cipher - Decipher (4.7@32) 2 LastUpdate: 2017-06-09 Caesar Cipher, Vigenere Cipher, Playfair Cipher …
Cryptography - Collection of ciphers and hashes (4.6@2,583) Ǥ 8
⭐Message/Text Encryptor - Secure Encryption.⭐ (4.6@5) 3
Decrypto (4.5@2,856) 4 LastUpdate: 2017-09-30 / DecryptoPro (4.7@157; ~EUR 1.75) 5 LastUpdate: 2017-09-30
Cipher Tools (4.5@8) 2
Cipher tools (4.4@813) 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 Solver (4.4@158) 0 $Contains no known trackers \o/$ LastUpdate: 2016-11-10 Caesar, Vigenère …
Cipher Decoder Cipher Solver (4.2@2,080) Ǥ 7
Encrypt Decrypt Tools (4.2@249) 2
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;
Universal Encoding Tool (4.1@145) 0 $Contains no known trackers \o/$
Cryptodroid (4.1@36) Ǥ 4 LastUpdate: 2016-06-18 Caesar cipher shift and Columnar transposition
CryptoTool (3.9@15) Ǥ 7 LastUpdate: 2016-11-08
Cryptography Mean™ - Encryption, decryption tools (3.7@3) Ǥ 5

Text encryption with PGP

2019-08-09

Latebra cryptographic app (4.5@6) Ǥ 21 encrypt SMS/Email
OpenKeychain: Easy PGP (4.4@2,662) Ǥ 20 Github; Kurzvorstellung 7/2015; Video Howto 9/2016 (DE)
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 (3.7@99; ~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@84; ~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@36) 5 $Contains no known trackers \o/$ / PGP KeyRing (3.6@56; ~EUR 3.00) 6 maintain your PGP keyrings

Encryption with AES/DES

2019-08-09

Private Notepad - notes, checklist & reminders (4.7@31,851) Ǥ 14
Encrypt It - MkII (4.7@35) 0 $Contains no known trackers \o/$ LastUpdate: 2014-05-14
Notepad with password FREE (4.6@2,892) Ǥ 6 / Notepad with password PRO (4.2@62; ~EUR 2.50) 2
DCipher (4.6@5) 2 Github
SealNote Secure Encrypted Note (4.5@2,921) 2 $Contains no known trackers \o/$ LastUpdate: 2017-04-13 Github; Video Intro 4/2017
AES Message Encryptor for SMS (4.5@117) 0 $Contains no known trackers \o/$ LastUpdate: 2017-01-15
SSE - File/Text Encryption & Password Vault (4.4@2,652) 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 text with CryptMax (4.4@75) 2 LastUpdate: 2017-01-18
Sec Notes- Free Secure Notepad (4.2@1,013) Ǥ 10
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@19) Ǥ 14
CrocodileNote (3.6@13) 2 $Contains no known trackers \o/$ LastUpdate: 2015-03-13 Github; AES-256 encrypted notes
Encrypt It (3.5@123) 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 $Contains no known trackers \o/$ Github

Messenger with encryption

2019-08-13

VIPole Private Messenger (4.6@9,886) Ǥ 22 also available for Windows, Linux and Mac OS, paid subscription needed for end-to-end encryption
Signal Private Messenger (4.5@341,504) Ǥ 48 Testbericht 11/2013; Vorstellung 11/2015 | 11/2015 | 11/2015 | 8/2018; "Crypto-SMS" und verschlüsselte Telefonie (ehemals TextSecure + RedPhone) | 11/2015
Threema (4.5@56,914; ~EUR 3.00) Ǥ 26 / Threema QR Scanner Plugin (4.1@7,868) 1 $Contains no known trackers \o/$ Test 4/2016; Vorstellung 2/2014 | 2/2014 | 2/2014 | 8/2018 | 11/2018; Wikipedia DE|EN; Audit 11/2015; Tipps & Tricks 12/2015; Anrufe 9/2017; Backup Tipps 10/2017; messenger with end-to-end encryption
Quicksy (4.5@50) Ǥ 21 Github; fork of Conversations using your phone number as ID
whispeer Messenger (4.5@30) Ǥ 17 Github; DerStart 8/2015; FU-Berlin 5/2017
Telegram (4.4@3,896,444) Ǥ 38 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
Conversations (Jabber / XMPP) (4.4@1,557; ~EUR 2.50) Ǥ 21 / Conversations Legacy (4.4@135) 14 $Contains no known trackers \o/$ / Share Location Plugin (4.6@59) 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; Vorstellung & Schnelleinstieg 5/2016; Anleitung für Anfänger 7/2018
[Old] Riot.im (4.3@1,303) Ǥ 29 Github; Kurzvorstellung 12/2016
Kontalk Messenger (4.3@580) Ǥ 32 Github; Vorstellung 8/2018
Nextcloud Talk (4.3@388) Ǥ 22 Github
Pix-Art Messenger (XMPP / Jabber Client) (4.3@74) Ǥ 24 Github; fork of Conversations
mini Vector (4.3@15) Ǥ 14 $Contains no known trackers \o/$ Github; riot client; see here for privacy issues with the Matrix/riot network
surespot encrypted messenger (4.2@2,923) Ǥ 11 Github; Vorstellung 2/2014; Wikipedia DE|EN; send encrypted messages. unlock voice messages per in-app payment. AES end-to-end encryption.
Wire • Secure Messenger (4.1@30,286) Ǥ 16 $Contains no known trackers \o/$ Testberichte 4/2017; Privacy-Warnung 7/2018; Vorstellung 8/2018; free/gratis, encrypted communication: voice, video and group chats; cross platform: Android, iOS, Mac, Windows. Or in the web browser.
Wickr Me – Private Messenger (4.1@17,781) Ǥ 20 Vorstellung 9/2013; Intro 9/2013; Wikipedia EN; end-to-end encryption with mission-impossible-flair (self-destructing messages)
Xabber (4.1@11,698) Ǥ 11 / Xabber (4.5@734) 8 $Contains no known trackers \o/$ LastUpdate: 2017-05-15 Vorstellung 8/2012 | 11/2013; Testbericht 8/2013 / Github
Briar (4.1@353) 15 $Contains no known trackers \o/$ / Briar Beta (Unreleased) (0@0) 9 Video Intro 7/2017; Video Review 7/2018; Vorstellung 9/2018 / Kurzvorstellung 2/2018; Source & Issues
Hoccer – the secure Messenger (4@7,916) Ǥ 14 Vorstellung 8/2018
TigerConnect - Clinical Solutions (4@4,930) Ǥ 29
Chiffry Secure Messenger (4@859) Ǥ 22
Zom Mobile Messenger (4@222) 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
aTalk (Jabber / XMPP) (3.9@42) 22 Github
Secure MMX Encrypted Messenger (3.9@28) Ǥ 14 $Contains no known trackers \o/$ LastUpdate: 2016-11-20
ginlo (SIMSme Private) (3.6@15,822) Ǥ 17 Vorstellung 9/2018
Rocket.Chat (2.9@1,425) Ǥ 16 Github; chat with screen and file sharing, and more
Delta Chat (0@0) 15 Github; Vorstellung 6/2019
Conversations with IPv6 (0@0) 20 $Contains no known trackers \o/$ fork of Conversations
Pattle (0@0) 1 $Contains no known trackers \o/$ client for riot/Matrix
Dib2Qm (0@0) 8 $Contains no known trackers \o/$ GitLab; based on IMAP and QuickMSG (no centralized server)

Also see: Verschlüsselte Messenger im Vergleich: Threema, Signal, Telegram, WhatsApp (11/2015 - 4/2017)

Various other encryption apps

2019-08-09

Cryptogram (4.7@796) 0 $Contains no known trackers \o/$ LastUpdate: 2012-05-31
Crypto - Tools for Encryption & Cryptography (4.6@219) Ǥ 11
Enigma Simulator (4.5@1,914) Ǥ 3 $Contains no known trackers \o/$ LastUpdate: 2017-07-14
Latebra cryptographic app (4.5@6) Ǥ 21 encrypt SMS/Email
TXTcrypt (4.4@79) 0 $Contains no known trackers \o/$ LastUpdate: 2016-06-28
Cryptogram Puzzle Quotes Game (4.3@1,424) Ǥ 5 LastUpdate: 2018-01-19
Oversec (4.3@170) Ǥ 4 $Contains no known trackers \o/$
Kryptomat (4.3@25) 2 $Contains no known trackers \o/$ LastUpdate: 2014-08-14
Crypto - RSA encryption by Cronkhinator (4.3@14) 1 $Contains no known trackers \o/$
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@5,107) 6 LastUpdate: 2017-11-12 Vorstellung 5/2012
PGPClipper (4.1@11) 3 Github
PixelKnot: Hidden Messages (3.7@1,035) 3 $Contains no known trackers \o/$ LastUpdate: 2017-02-19 Github; Details; Steganography (text hidden inside image, unlock with passphrase)
Enigma Trial - Cryptograms (3.2@182) 0 $Contains no known trackers \o/$ LastUpdate: 2017-12-09 / Enigma - Cryptograms (4.4@161; ~EUR 1.00) 0 $Contains no known trackers \o/$ LastUpdate: 2017-12-09
Encrypt Editor (3.1@32) 5
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)

2019-08-18

IzzyOnDroid