MainWP is described as 'suite of open-source self-hosted plugins & extensions for users that have multiple WordPress sites and want to be able to control them from one central location. This includes sites on different hosts or servers'. There are eight alternatives to MainWP for Online / Web-based, Wordpress, Self-Hosted solutions and SaaS. The best alternative is ManageWP, which is free. Other great apps like MainWP are WPMU DEV (Paid), InfiniteWP (Free Personal), WP Remote (Freemium) and iControlWP (Paid).
WP Remote provides a single place to monitor and update all of your WordPress sites. It can handle updates to installed plugins and themes remotely via the WP Remote website, and also provides quick access to core updates.