Unlike cats, Kamen Riders are a bit more complicated to catch the attention of; instead of setting out food and toys to attracts cats you set out items and a “heart of Justice” to bring them to your doorstep.
Shocker Combatants will occasionally show up as well, and you’ll see the Kamen Riders fighting them! once defeated they will drop more “heart of Justice” to attract an even bigger variety of Kamen Riders.
Kamen Rider Atsume is set to hit in Spring 2016 on iOS and Android. Probably won’t be in English unless it manages to become big enough a hit that they’ll release a translated version.