A system for developing software comprising: at least one processor; and at least one memory operatively coupled to the at least one processor, the at least one processor configured to acquire computer readable instructions stored in the at least one memory and execute the instructions comprising instructions to cause the system to: - provide a graphical user interface on a display of a client device, the graphical user interface displaying a plurality of features from a library of user-selectable features for a custom software application and implement simulations of a plurality of the features available for demonstration through the graphical user interface, the simulations being executable visualizations of associated features of the library configured to be displayed within the graphical user interface; - store blocks of source code for each feature in a source code repository, wherein the blocks are adapted to provide an actual application when compiled by developers; - receive from the client device, by a server running a software building component of a software development application, one or more selected features for the software application; - automatically integrate, by the software building component, the one or more selected features to generate an integrated feature set based on attributes of each of the selected features and an inter-feature rules set, and - generate on the graphical user interface an interactive visualization of a navigable prototype of the software application based on the integrated feature set and the corresponding simulations, wherein the inter-feature rules set define relationships or associations between features of the library of features, and the attributes of a feature comprise a first set of attributes configured to regulate how the feature is called, and a second set of attributes configured to regulate which features the feature calls. at least one processor; and at least one memory operatively coupled to the at least one processor, the at least one processor configured to acquire computer readable instructions stored in the at least one memory and execute the instructions comprising instructions to cause the system to: - provide a graphical user interface on a display of a client device, the graphical user interface displaying a plurality of features from a library of user-selectable features for a custom software application and implement simulations of a plurality of the features available for demonstration through the graphical user interface, the simulations being executable visualizations of associated features of the library configured to be displayed within the graphical user interface; - store blocks of source code for each feature in a source code repository, wherein the blocks are adapted to provide an actual application when compiled by developers; - receive from the client device, by a server running a software building component of a software development application, one or more selected features for the software application; - automatically integrate, by the software building component, the one or more selected features to generate an integrated feature set based on attributes of each of the selected features and an inter-feature rules set, and - generate on the graphical user interface an interactive visualization of a navigable prototype of the software application based on the integrated feature set and the corresponding simulations, - provide a graphical user interface on a display of a client device, the graphical user interface displaying a plurality of features from a library of user-selectable features for a custom software application and implement simulations of a plurality of the features available for demonstration through the graphical user interface, the simulations being executable visualizations of associated features of the library configured to be displayed within the graphical user interface; - store blocks of source code for each feature in a source code repository, wherein the blocks are adapted to provide an actual application when compiled by developers; - receive from the client device, by a server running a software building component of a software development application, one or more selected features for the software application; - automatically integrate, by the software building component, the one or more selected features to generate an integrated feature set based on attributes of each of the selected features and an inter-feature rules set, and - generate on the graphical user interface an interactive visualization of a navigable prototype of the software application based on the integrated feature set and the corresponding simulations, wherein the inter-feature rules set define relationships or associations between features of the library of features, and the attributes of a feature comprise a first set of attributes configured to regulate how the feature is called, and a second set of attributes configured to regulate which features the feature calls.