I have created a little game called scribi ( currently just available for iOS) https://scribi.web.app My question would be how would you make it grow? Any ideas on what to implement so that maybe players invite their friends?

I'm not an expert, but I'd try an offer an insentive for those who invite their friends. Like a badge, or extra "coins".

Ah thats a good idea, i will put that on my todo

To be on Android as well. Have you published your game on other platforms so more people can see and install your game.