Here are few software I use for Amateur Radio.

MixW Software for psk, rtty, fax, sstv & more

CHIRP freeware to program radios

GAL-ANA Antenna radiation simulator 

SDRUNO SDR software

SDRSharp SDR Software with plugins for more fun

HDSDR SDR Software

RTL1090 ADS-B Radar 

Spectrum Lab Audio spectrum Analyzer used for Radio Astronomy 

WTR Browser Swiss Army Knife for Frequency Searches

Peanut App for D-star & DMR by PA7LIM