Updated final_invoice_app
Updated invoice_app
Updated soa_app
Updated README.md
Revert "Updated README.md"

This reverts commit e98ea1b169170f5ee8a785954ab1349a84c93daa.
Revert "Revert "Updated README.md""

This reverts commit c387624c8b06d1c51e7b2fc5951da04dfe89c2fd.