Synthesia is a software which teaches you to play piano using piano-roll-style falling notes with any MIDI file. You can choose more level

Worker is a file manager much like the Amiga's DirOpus. It can be controlled with mouse or keyboard. There is no restriction on the number or type of button functions. Files are recognized by both extension and content, content by recognizing common bytes in the sample files you show it. Drag & Drop is supported.

The hddtemp program monitors and reports the temperature of PATA, SATA or SCSI hard drives by reading Self-Monitoring Analysis and Reporting Technology (S.M.A.R.T.) information on drives that support this feature.

GNOME-Colors is a set of GNOME icon themes, with some inspiration from Tango, Elementary, Discovery, Tango Generator and others.

i7z reports Intel Core i7, i5, i3 CPU information about Turbo Boost, frequencies, multipliers, ... and comes top-like display showing per core the current frequency, temperature and times spent in the C0/C1/C3/C6/C7 states.