Yes, absolutely. All fan-made Kamen Rider simulators are, and should always be, free. If you see a website trying to charge you for this download, it is a scam. Developers like "xxxiranook" create these apps purely out of passion for the series.
: Built using Flash (ActionScript), utilizing modular sprite-based animations to mimic the physical movement of the Decadriver. kamen rider neo decade simulator ver 30 1 exclusive
The belt automatically closes, triggering the signature mechanical transformation sounds and flashing LED sequences unique to that Rider. Yes, absolutely