I'm in the same situation. Switched to damn iPhone just because of the apps, and playing with my beloved windows phone (Ativ S) without a sim card. I'm really excited about MS future products (bands, holothings, windows 10) and I love how their services integrate with devices. For instance, iCloud Drive is underfeatured and a messy thing in comparison of OneDrive. But... but I'm really disappointed by big developers.
One app I use a lot is LinkedIn. On WP is just cr4p, they don't update the app since december 2013 and it doesn't integrate with WP share men? (I share a lot of content on LinkedIn through RSS readers). It lacks a lot of features. Same thing for Tripadvisor, Instagram, and so on. Not talking about other "big" apps that are actually missing like Snapchat, Booking.com, and so on.
I really hope MS will invest some money to make those enterprises developing universal apps in time for windows 10 release. Putting money in this areas would work better than throwing them in advertising low and mid range phones IMO, at least in this phase where the app gap is still here. Hope things will change during the next months.