Messenger with the ability to create group chats without restrictions?

Question

Android

Hello. Please tell me, is there a messenger for iOS and Android in which you can make a group chat without limiting the number of participants? For some reason, in the most popular messengers, the limit is up to 100-200 people in a group. In 4talk there were no limits, but recently they made up to 200. In icq8, you can do it without limits, but each participant can remove the other (and this is not the case in the wp8 version) from the chat, and can rename the group.
We want to make a city chat for 3000 people (for now), but we don’t know what messenger to use. It is desirable that there be registration through a phone number, as in whatsapp and viber.
Thanks in advance for your replies.

Answer 1

ICQ - no limits
Skype record holder - up to 300 people, followed by Facebook Messenger - 250 users, Telegram - up to 200, followed by Hangouts and 150 people, then WhatsApp and a maximum of 100 users. In the tail were Viber - up to 40 people.
January 2015 info

Answer 2

How about IRC, or your own Jabber server + any XMPP client?

Answer 3

IRC for such cases has existed for several decades. Moreover, it works great on the mobile network, because the protocol was invented in those days when a ping of 120 seconds was not an amazing event.
From android clients - I liked AndiChat at one time.

Answer 4

Skype? mail.ru agent?