Regarding your project description can you please clarify which type of apps you are looking for.
Hello Dear,
Hope you are fine.
My self Ali Ravani i am working on odoo from version 6 to current 12, having 6 years of experience.
I have done customisation in existing odoo apps as well as created new apps from scratch.
Also know third party api like amazon, ebay, shopware, shopify, xero, magento, paypal, shipcloud(multi delivery carrier under one platform), bigbuy, woo-commerce and can do many more.
Please let me know if you need more information
Thanks and regards,
Ali Ravani.