We have done complex customization in OpenCart and integrated customized MarketPlace Multivendor extension in it.
This app helps the user to buy very specific gifts for his/her relative, friends, etc. Users can share payments with friends, relatives, etc.
Market places allow vendors to post their products and specify product specs so specifically, that helps users to buy best match products for themselves, friends, & relatives, etc.
There are many more features in the app such as Real-time notification, quick way for vendors to manage their stock & sales, pay vendor payment in few clicks, nice dashboard for admin & vendor, etc..!!
Users can chat with their friends, relatives, etc.. via the app and share ideas for buying products Built with.