I can't make a full list because it'll take much time.
Well, this is exactly what I was looking for. Let me tell you why I don't feel the app gap. (though after seeing all these I have to accept there is an app gap).
SNS:
Facebook: I use the Facebook Beta. For features that it miss, like adding feelings or photo commenting, i use the mobile website. Since I don't do those that often, the app seems to be more than enough.
Twitter: Official app. I manage the account of a brand and the app is fine. During peak hours I switch to Tweetdeck on lappy since I had to manage a lot of feeds at the same time.
Instagram: 6tag is my choice. I don't use Insta much.
Messaging:
Whatsapp: No real limitations.
Messenger: Calling. But again, this has very limited use in India. And for my friends abroad, i prefer Viber.
Hike: No limitations.
Cricket:
This is one app that i definitely want. And cricbuzz and espncricinfo do really fine job. And there is CricHQ. No complaints in this part either.
Banking:
I use HDFC and they are having a full featured app since a long time. And recently i switched to Kotak and brought them to WP along with me. :evil:
Navigation:
Here Drive (not plus yet) works like a charm.
Music:
MixRadio hands down. There is one problem with MixRadio though. It don't differentiate between languages. In a country with 20 major languages this is a must. But over the course due to my listening pattern (or that is what i guess), now it shows only songs from my language.
Games:
Okay. I'm not a big gamer. For casual gaming, I have Jetpack Joyride, 2048, Piano Tiles, Hypernaut, Poko.
And two big titles (> 50MB) Guardians of the skies and OverVolt.
News:
There is a lot here for me. NDTV, IBNLive (they haven't updated the app in a while, but still that's fine), TOI, and a couple of local language apps.
Browser:
IE is awesome. But as backup I use UC.
That covers the entire thing. Photos is one area I'm not fond of but I still have Fotor.