I think this will deviate the topic pretty far. These are just apps I frequently use;
Ones that kind of exist on Windows Phone, but suck
Instagram
Kindle
Facebook
Twitter
Amazon Shopping
Ebay
Roku
Waze
Wordpress
Yelp
Apps I use that don't exist on Windows
Google Music
Amazon Music
AMC
Android Pay (i would count it if there was a windows pay)
AO Surgery Reference
Chase
Comedy Central
Synology suite of apps (downloads, files, music, videos, etc)
Dragon Medical Dictation
Fandango
FXNow
Netgear Genie
GPB Georgia
NCCN Guidelines
HBO Go
Kroger
Lowe's
Medscape
Facebook Moments
Slick Deals
Snap Chat
Starbucks
Taco Bell
Xfinity TV Go
Xfinity TV Remote
Twitch
Uptodate
Hardware Specific Stuff
Quick Remote (IR BLASTER)
Gems of Windows platform
1. Bookviser reader - 3D page rotation, multiple formats including Epub, Universal and FREE.
2. myTube - Universal, lets us save video/music directly to SD card, beautiful UI
3. Magnify Reader - UI will literally blow your mind. It's amazing!
4. Saavn / Gaana - Awesome universal app for music streaming and downloading in India
5. Flipkart - Online shopping (India) - Supports voice search and friends recommendation, can pin your favourite products to start screen. Live tiles shows the latest price and offers if any.
6. Readiy - Awesome feed reader for PC
7. AppRaisin
8. Adobe photoshop express
7. HERE suit of apps (City Lens, maps, drive, transit)
8. Office suite of apps(many win 10 machines/smartphones get free 1 year office 2016 subscription)
9. Action Note - Integrates note taking into action centre and synchronizes that across Win 10 PC and smartphones with a common login. Cannot live without this app.
10. wpTorrent - The best torrent client on a smartphone available exclusively on Windows smartphones(WP8.1). Saves files directly on SD card.
11. Advanced English Dictionary - This is the best dictionary app available on Win 10 PC and smartphones. Live tiles displays the word of the day and its meaning!
12. Audible
13. BookMyShow - Universal app - exists on PC and smartphones (India)
14. IRCTC - Official Indian railway ticket booking app arrived first on Windows smartphones and PC!
15. Ouga - An awesome 3rd party app for Tumblr - PC & smartphones
16. Squid - An awesome note taking app
17. Fresh Paint - An awesome painting and sketching app
18. WhosDown - WhatsApp client for Windows 10 PC - better than nothing!
19. Lumia camera suite of apps - Creative studio, cinemagraph, Lumia camera, Panorama, Selfie
I can go on and on. But my point was to highlight the fact that some developers are really working hard to make awesome apps exclusively for Windows platform. Android may have more number of apps but thanks to these developers, Windows platform today is giving a tough fight to Android and iOS. Let us appreciate the efforts of those Windows developers.