Have you heard about IPFS?
Like some said, it is pretty difficult to have Messenger built on Blockchain. IPFS is a good Blockchain alternative. I think messager can be built on it.
A crypto company called "Status"
https://status.im is also building a decentralized messaging platform that is a somewhat similar to Telegram. You can Chat, trade and exchange Cryptos on the platform.
Am not very sure if they are creating it on Blockchain or IPFS.
There are two others called "Sola"
https://sola.foundation/ and "Obsidian"
https://osm.obsidianplatform.com. I think Sola has a working product. I have their app on my phone but haven't really tried it.
You could learn from them or just use their products.
I'd recommend "Status". They have an invite-only App on Playstore at the moment.
I think Status would work great. Better to just wait for them.
Do not be discouraged if you still want to build one yourself.
