Stellarium (Free)  Very good Home Planetarium. Useful for checking views from telescopes/cameras
AstronomyTools (Free, Online) Suitability calculator and FoV tools 
Telescopius (Free, Online)  Good for Field of View Calcs, Create account to save config
Virtual Moon Atlas (Free)  Download app for Windows/Linux. Very detailed study of the Moon
Carte-du-Ciel (Free) Very configurable. Less easy to understand. Good to use for OTA GoTo. Extendable 
NINA (Free)  Schedule Whole Capture Session c/w plugins - Has Best Target viewer
SkySafari Plus Smartphone (Free/Premium)  Phone/Tablet. Good for FoV. Apple / Android 
Hallo Northern Sky (Free / Open Source)  Planetarium for Windows/Linux, ASCOM & INDI Control 
Polar Finder (Free)  For polar alignment (EQ setup) 
Polar Scope Align (Free)  For polar alignment (EQ setup) 
Polemaster (Paid)  Comes with camera 
ISS Transit Finder (Free, Online)  Calculates ISS and Tiangong transits of the Sun & Moon for your location
Light Pollution Map (Free, Online)  Shows Sky Brightness and Bortle Scale overlaid on map
Deep Space Network (Free, Online)  Shows which radio telescopes in the DSN are working with which satellites

NINA (Free)  Full capture application. Advanced Sequencer steep learning curve
ASI Air (Paid)  All in one unit for OTA control & image capture. ZWO and DSLR cameras only
Astro Photography Tool (Free)  Replaced with NINA (DOS front end)
KSTARS/INDI/EKOS (Free)  Full capture & rig control application (Linux / Windows)
Stellarmate (X) (Paid)  Lightweight hardware control & image capture
Intervalometer (Cheap)  Basic hardware controls exposure only Amazon / Ebay
Firecapture (Free)  Planetary / Solar / Lunar. High-quality results
SharpCap (Free/Paid)  Included in QHY bundle. Planetary capture. Polar Alignment
Skywatcher Synscan (Paid)  Phone App via wifi. Finding targets and capturing
Sequence Generator Pro (Free/Paid)  Session Control for Windows, similar to NINA

Deep Sky Stacker (Free)  DSS 5 available. Deep sky only
Registax (Free)  Comprehensive stacking & Wavelet Sharpening
Autostakkert (Free)  Easy to use comprehensive stacking with drizzle functions
Siril (SirilC) (Free)  Stacking and image processing. Scriptable and extendable 
Affinity Photo (Paid)  Multi-session capable stacking & Processing Tool
PIPP (Free)  Video preparation tool for later stacking
Starstax (Free)  Basic for star trails and ISS stacking
Sequator (Free)  Simple stacking tool. Good for Star trails & Milky Way
Astro Pixel Processor (Paid/Trial)  Comprehensive stacking tool. Mosaic & Multisession
PixInsight (Paid)  Expensive when add extras. Definitive "pro" tool. Steep learning curve
ASTAP (Free / Open Source)  Stacking, Plate Solving, Astrometry, Photometry

Affinity Photo (Paid)  Good company Support (James Ritson Free addons)
PixInsight (Paid)  Expensive when add extras. Definitive "pro" tool. Steep learning curve
GIMP (Free)  OpenSource general image processor. Well supported (YouTube) 
PIPP (Free) Video manipulation tool
Siril (SirilC) (Free)  Stacking and image processing. Scriptable and extendable
GraXpert (Free) Background gradient flattener and Denoise
Astrosharp / Astroclean (Free)  Deconvolution / Denoise tools. Lunar & Planetary
WinJupos (Free)  Derotation capability for planetary
Startools (Paid)  Off the wall image processing (Holistic)
Starfixer (Free, Online)  Star reducer 
Photoshop (Paid / Subscription)  Industry standard image processing
Starnet++ (Free)  Removes Stars from images
StarXterminator (Paid)  Star removal tool for Pixinsight and Affinity Photo
Image16 (Free / Open Source)  Competent processor with many features

Meteoblue 
Metcheck
ClearOutside
SAT24
Weather & Radar
Netweather.tv 
Windy.com
Openweather API