Free File Splitter - File Splitter is a handy freeware program which allows to easily split and merge files
dupeGuru - dupeGuru is a tool for finding duplicate files on your computer.
GSplit - GSplit is a free file splitter that splits any file into smaller files called pieces. Lots of customization options, attractive and easy-to-use interface.
Duplicate Cleaner - Duplicate Cleaner: the fastest and most popular tool for finding duplicate files. Over 1 million downloads: Get your copy now! Free and Pro versions available.
Batch File Split & Join - Split and merge multiple text or binary files in either character, line, or byte modes. When splitting files, you can split on certain text or binary separator; target given number of parts; or target specific part size. Join files on lines/bytes.
Czkawka - Multi functional app to find duplicates, empty folders, similar images etc.