The Insteon Hub is good for small jobs or basic needs like remotely switching lights on/off, and simple on/off schedules. The Hub app for iOS or Android, is used to add Insteon devices and set up scenes as well as timers/schedules. The app MUST be used for initial configuration. Service is cloud based, and once set up, a web based log-in can also be used. Only one on/off time per scene can be set. A device must be added to a scene to be scheduled.
The ISY994 is suitable for larger installations, or where you want multiple schedules or more complex schedules. It also enables conditional logic (eg. if it's after 9pm and the door opens, turn on the light). You can also add Zwave support (future module), or software upgrades to support weatherbug, network device control, Elk alarm integration etc. Configuration and programming is done with a browser interface using Java. Apps are available from 3rd parties, for iOS and Android. ISY994 also supports demand-response integration for hydro.