The user-friendly interface has three tabs: Splitting, Joining, and MD5 Checksum.
In the Splitting section, you select the source file and the output directory. Then you can either choose from splitting the file into the desired number of parts (which are equal in size), or splitting the file after every given number of storage units (expressed in bytes, kB, MB, or GB).
The latter option is recommended when you know the exact size of the source you wish to use for transferring the split file.
You can also delete the source file after splitting, and use a password to encrypt parts.
In the Joining section, you select the source of only the first part (in case all split parts are in the same source), as well as the output file.
If the split parts are in separate folders, then File Joiner will compile all the split parts found in the source of the first one, after which you will be prompted to provide the path to the missing part.
There is also the option of deleting split parts after joining.
Files Splitter and Joiner has The MD5 Checksum section which contains MD5 signature, which is an algorithm that verifies data integrity between transferred files (you can compare two files to see if they are identical in signature).