IIS*Case is a software tool that provides information system modeling and prototypes generation. At the level of platform independent model specifications, IIS*Case provides conceptual modeling of database schemas that include specifications of various database constraints, such as domain, not null, key and unique constraints, as well as various kinds of inclusion dependencies. It also provides conceptual modeling of business applications. In the paper, we present new concepts and a tool embedded into IIS*Case, that is aimed at supporting specification of check constraints. We present a domain specific language for specifying check constraints and a tool that enables visually oriented design and parsing check constraints. Also, we present concepts and a tool that is aimed at supporting specification of complex (i.e. "nonstandard") functionalities of business applications. It is provided visually oriented and platform independent specification of business application functions.