This app was mentioned in 4 comments, with an average of 3.25 upvotes
Mobile:
PC: You should be mainly looking at the real-time strategy genre. /r/RealTimeStrategy
StarCraft II currently has the largest community, but the game is not very noob friendly. There is a starter edition available for free that offers a decent amount of gameplay, although not ranked. /r/starcraft
Age of Empires 2 HD has the second largest community, but the game is old/classic and is mostly popular with nostalgic people. /r/AoE2
Command & Conquer is the first series many people think of when they think of real-time strategy, but EA screwed up the franchise so there haven't been any new games recently.
8-Bit Armies is a new indie game that is trying to bring real-time strategy back into the spotlight.
You can also find multiple versions of Stick War and Age of War browser games.
Mobile:
League of War: Mercenaries is similar to Clash Royale but from a side view rather than a bird's eye view.
Stick War: Legacy is another side-view game that's closer (but still not that close) to conventional RTS.
Age of War is like a Stick War - Rise of Nations hybrid.
This Means War! is like a Clash of Clans and Clash Royale hybrid.
PC: You should be mainly looking at the real-time strategy genre. /r/RealTimeStrategy
StarCraft II currently has the largest community, but the game is not very noob friendly. There is a starter edition available for free that offers a decent amount of gameplay, although not ranked. /r/starcraft
Age of Empires 2 HD has the second largest community, but the game is old/classic and is mostly popular with nostalgic people. /r/AoE2
Command & Conquer is the first series many people think of when they think of real-time strategy, but EA screwed up the franchise so there haven't been any new games recently.
8-Bit Armies is a new indie game that is trying to bring real-time strategy back into the spotlight.
You can also find multiple versions of Stick War and Age of War browser games.