Your new Android comes with dozens of pre-install apps. Some of them are useful while some of them are just bloatware (I am looking at you Samsung) People often don't realize that there are better alternatives to these stock pre-install apps. For instance, you can replace Google maps with Here maps. It works same as Google maps and offers additional features like taking the entire country's map offline. Similarly, you can replace other stock apps with their better alternative. Following table shows which stock apps you should replace and Why? What do we gain by doing that? So let's get started.

                             Replacement Apps for Android
Stock App Replacement App Why?
Google Play  Shuttle Support for lyrics, gapless playback, sleep Timer, themes
Gallery  QuickPic Password protect selected images, Faster and better UI, Support gif, Cloud Backup
Video Player  MX player Support all type of video format, subtitles, sound boost up to 200%, Network streaming
Facebook Tinfoil for Facebook Requires no special permission, privacy-friendly, send message directly from the app
Stock Launcher Nova Launcher Lets you customize every bit of UI and yet extremely stable
YouTube OG YouTube Download, or play videos in floating window or when the screen is off.
Contact Contact+ Auto Sync contact's information from Facebook, Twitter, and Google+
Google Maps Nokia HERE Details maps, Download entire city or country maps, and shows speed limit
Calendar Sunrise Enter text in a natural language and it will auto fill all entry. Facebook, Evernote and Asana integration
Stock keyboard  Swift keyboard More customization. Adapt and predict words as per your typing habits
Imgur  Opengur Material design, better functionality and support gifs