Features:
• hashing algorithms: MD5, SHA-1, SHA-256, SHA-384, SHA-512
• single file hash calculation
• recursive checksum generation/verification
• RegEx file name filter (hold "Make Snapshot" button)
• md5sum, md5summer compatibility.

About performance.
According to the Play Store policy regarding the use of the "Access to all files" permission, application performance has a lower priority and cannot be a reason for obtaining it. Therefore, this application uses SAF (Storage Access Framework), which has a huge performance impact, especially when recursively traversing directories with a large number of small files.