EDS – encrypt your files to keep your data safe
truecrypt kompatibel, container:  FAT, AES256 & Hash SHA 512
( https://stadt-bremerhaven.de/eds-lite-truecrypt-unter-android-lesen-und-kompatible-container-erstellen/ )
https://play.google.com/store/apps/details?id=com.sovworks.eds.android&referrer=utm_source%3DAndroidPIT%26utm_medium%3DAndroidPIT%26utm_campaign%3DAndroidPIT&showAllReviews=true

SSE - File/Text Encryption & Password Vault
https://play.google.com/store/apps/details?id=com.paranoiaworks.unicus.android.sse&referrer=utm_source%3DAndroidPIT%26utm_medium%3DAndroidPIT%26utm_campaign%3DAndroidPIT
⬥ open source, 
⬥ Cross-platform desktop versions (Windows, Linux, Mac OS X, …) of the Text Encryptor and File Encryptor are available on: https://paranoiaworks.mobi

EgoSecure Encryption Anywhere
https://play.google.com/store/apps/details?id=com.egosecure.uem.encryption&referrer=utm_source%3DAndroidPIT%26utm_medium%3DAndroidPIT%26utm_campaign%3DAndroidPIT




Boxcryptor


Cryptomator


SecureSafe