Aspects described herein may be used with local spreadsheet applications, web, and/or cloud- based spreadsheet solutions, to create complex custom software applications. Spreadsheets themselves lack the conceptual framework to be used as a platform tool to build custom or complex software applications. Using methods and systems described herein using low-code/no-code techniques, a designer can create custom and/or complex software applications using one or more spreadsheets as the underlying blueprints for the software application. The resultant software application may be static/read-only, or may be interactive to allow users to dynamically add, delete, edit, or otherwise amend application data, e.g., via one or more online web pages or via a mobile application. Data transfer may be one-way or bi-directional between the blueprint spreadsheets and the resultant software application, thereby allowing amended data to be transferred from the software application back into spreadsheet form.