A custom Sonic Runners server is on the way, runned and owned by You-Are-Pwned (Sonic Retro)
Looks like this game is not kicking the bucket anytime
You-Are-Pwned is creating a private server for Sonic Runners so that everyone can play this game once again.
Huge thanks to You-Are-Pwned for making this possible!!
The apk for it will be released very soon. No news on the iOS version yet.