Thanks for playing and welcome to RetroFab! I'm currently in the process of updating all simulations to the latest version (0.9.10) and making them downloadable. Those I haven't got to yet will be completed in the next few weeks. Followers are notified when simulations are updated and available for download.
Thanks for your offer to contribute rom files, but these simulations do not make use of rom files. Contributors provide videos of gameplay and scans of the graphics and instructions to make the recreations possible.
A number of simulations of Tiger handhelds are planned, including Castlevania! You can find details provided by the contributor for the simulation in this topic and a preview of the initial prototype here.