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

2025-06-11

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 Cipher Disk (4.8@200) 1 $Contains no trackers known to us \o/$ LastUpdate: 2021-08-09
ROT13 Translator (4.8@100) 0 $Contains no trackers known to us \o/$ LastUpdate: 2014-07-20
Caesar cipher - De-/Encryption (4.5@277) 2 $Contains no trackers known to us \o/$ LastUpdate: 2023-11-02
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

2025-06-11

Morse Mania: Learn Morse Code (4.8@31,375) 8 2
Morse Trainer (4.5@6) 0 $Contains no trackers known to us \o/$ LastUpdate: 2023-05-31 Github
Morse Mentor (4.4@366) 4 $Contains no trackers known to us \o/$
G0HYN Learn Morse (4.4@108) 1 $Contains no trackers known to us \o/$
Morse code - learn and play (4@771) 6 2 LastUpdate: 2020-06-05
Mors. : The Morse Code Trainer (3.3@388) 2 1 LastUpdate: 2020-06-15
Morse Audio - Morse Code Learn (1@42) Ǥ 3 1 LastUpdate: 2018-12-03
Dahdidahdit — The Morse Trainer (0@0) 4 $Contains no trackers known to us \o/$ Github

General Morse apps

2025-06-11

BF4 Lantern & Morse Solver (4.7@1,232) 4 1 LastUpdate: 2020-07-21
Morse (4.6@50) 3 $Contains no trackers known to us \o/$ Github
Morse Code (4.3@7,797) 7 1
M³ Translator: Morse code (4.3@5,376) Ǥ 12 2 LastUpdate: 2023-08-17
Pocket Talk (4.3@6) 5 $Contains no trackers known to us \o/$ LastUpdate: 2016-01-13
Morse Code Reader (4@2,040) 2 $Contains no trackers known to us \o/$
morsee : Enjoy Morse code (4@1,291) Ǥ 7 4
Morse Transmitter (3.8@1,093) 1 $Contains no trackers known to us \o/$ LastUpdate: 2014-01-20
Morse (3.7@1,761) 5 2 LastUpdate: 2018-03-10
Morse Code Translator (3.6@2,944) Ǥ 11 3 LastUpdate: 2022-12-14
Morse Me (3.5@87) Ǥ 9 4 LastUpdate: 2020-05-28
SMS-Morse (1@20) 0 $Contains no trackers known to us \o/$ LastUpdate: 2022-04-07

Morse Keyboards

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DotDash Keyboard (4.3@282) 1 $Contains no trackers known to us \o/$ LastUpdate: 2020-05-20 Github
MouseCode Keyboard (4@5) 1 $Contains no trackers known to us \o/$ LastUpdate: 2017-03-01
Morse Code Keyer (3.6@178) 4 1 LastUpdate: 2020-02-23
Morse Code Keyboard (3@141) Ǥ 5 2 LastUpdate: 2018-12-08

Multiple text-encryption methods

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Coooder (4.7@6) Ǥ 5 4 LastUpdate: 2019-02-09
Cipher Decoder - Cipher Solver (4.5@2,599) Ǥ 7 4 LastUpdate: 2019-05-15
Cryptography (4.4@3,441) Ǥ 8 2
Decrypto (4.3@3,943) 4 1 LastUpdate: 2017-11-10
Cipher Solver (4.2@188) 0 $Contains no trackers known to us \o/$ LastUpdate: 2016-11-10 Caesar, Vigenère …
Universal Encoding Tool (3.7@140) 0 $Contains no trackers known to us \o/$
Cryptography Mean™ - Encryptio (1@5) Ǥ 5 1 LastUpdate: 2018-07-24

Text encryption with PGP

2025-06-11

Latebra cryptographic app (4.6@8) 17 2 encrypt SMS/Email
OpenKeychain: Easy PGP (4.1@4,299) Ǥ 19 $Contains no trackers known to us \o/$ Github; Howto 12/2017 | 2/2019; Anleitung 8/2020 | 11/2020; Wikipedia DE | EN
Tessercube (1@30) 20 $Contains no trackers known to us \o/$ LastUpdate: 2020-07-25 Github
OkcAgent (0@0; ~EUR 1.00) 3 1 LastUpdate: 2020-11-24 Github; make OpenKeychain available in your Termux shell

Encryption with AES/DES

2025-06-11

AES Message Encryptor for SMS (5@158) 0 $Contains no trackers known to us \o/$
Cryptool (4.8@241) 9 $Contains no trackers known to us \o/$ Github
SSE - File & Text Encryption (4.3@3,909) Ǥ 7 $Contains no trackers known to us \o/$ GitLab; Password-Safe, texts, files, and more; cross-platform (Windows, Linux, Mac OS X, …); Open Source
Notepad with password (4.3@3,706) 8 4 LastUpdate: 2023-08-07
Private Notepad - safe notes (4.2@49,386) Ǥ 16 4
Sec Notes- Secure Notepad (3.9@1,544) Ǥ 17 2
SimpleTextCrypt (0@0) 1 $Contains no trackers known to us \o/$ Github
SecureYourChats (0@0) 5 $Contains no trackers known to us \o/$ Github
DroidCrypt (0@0) 4 $Contains no trackers known to us \o/$ Github; files & text with AES
Encrypt Text (0@0) 0 $Contains no trackers known to us \o/$ LastUpdate: 2020-08-23 Github
KeyCip (0@0) 7 $Contains no trackers known to us \o/$ LastUpdate: 2022-07-17 Github

Various other encryption apps

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Safe Notes is a secure notepad (4.8@5,281) Ǥ 12 2 LastUpdate: 2023-08-25
Enigma Simulator (4.6@2,202) Ǥ 6 1 LastUpdate: 2023-09-09
Latebra cryptographic app (4.6@8) 17 2 encrypt SMS/Email
Crypto - Encryption Tools (4.5@1,881) Ǥ 9 3
Oversec (4.3@259) Ǥ 4 $Contains no trackers known to us \o/$ LastUpdate: 2019-04-23
Enigma Trial - Cryptograms (4.3@182) 0 $Contains no trackers known to us \o/$ LastUpdate: 2017-12-09 / Enigma - Cryptograms (4.4@172; ~EUR 1.00) 0 $Contains no trackers known to us \o/$ LastUpdate: 2017-12-09
Cryptogram Puzzle Quotes Game (4@1,507) Ǥ 5 3 LastUpdate: 2020-04-26
PixelKnot: Hidden Messages (3.1@1,185) 3 $Contains no trackers known to us \o/$ LastUpdate: 2023-06-12 Github; Details; Steganography (text hidden inside image, unlock with passphrase)
Encrypt Editor (1@35) 5 2 LastUpdate: 2023-09-05
Privacy Keyboard : Secure text (0@0) 1 $Contains no trackers known to us \o/$ LastUpdate: 2023-08-17 Github; Keyboard for secure E2EE communication
Rivia (0@0) 0 $Contains no trackers known to us \o/$ LastUpdate: 2022-09-02 Github

Further Readings:

Category Encryption of Files and Folders
Category Messenger & Conferences

2025-06-22

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