postActiv has been discontinued. Similar apps include Mastodon, which is free and open source. Other options are Friendica, Pleroma, VK and GNU social. In total there are seven Social Networks like postActiv for the web, self-hosting, Android, iPhone and iPad.
Decentralized and federated social platform with no ads, focusing on personal interaction, and offering 500 character posts, custom emojis, content warnings, and robust moderation tools.
Germany
EU
Friendica is a distributed social network application. Which allow users to connect with others via their own Friendica server, but may also fully integrate contacts from other platforms including Twitter, diaspora*, Pump.io and StatusNet into their 'newsfeed'.
Australia
Pleroma is a free, federated social networking server built on open protocols. It is compatible with GNU Social, Mastodon, and many other ActivityPub and OStatus implementations.
VK (originally VKontakte) is a largest social network service from Europe. Available in many languages and highly popular particularly among Russian-speaking users around the world, especially in Russia, Ukraine, Kazakhstan, Moldova, Belarus, and Israel.
Russia
GNU social is a continuation of the StatusNet project. It is social communication software for both public and private communications. It is widely supported and has a large userbase.
United States
This is a fork of Pleroma, which is a microblogging server software that can federate (= exchange messages with) other servers that support ActivityPub. What that means is that you can host a server for yourself or your friends and stay in control of your online identity, but...
identi.ca is a free personal web server that implements a distributed social networking service. It is based on pump.io, a free software which make up the distributed social network.
Canada
