Cloudron is a self-hosted App-as-a-Service solution. It allows you to browse a market place of open source (with some exceptions such as Jira) apps to install. These apps are packaged as Docker containers with a specialized Cloudron Manifest file. Once you choose an app to install you just put in the subdomain you want the app to be hosted on and it will setup DNS records and install the app for you.
Cloudron does it's best to secure your server and keep it updated as well. It will even request reboots to install certain packages like Kernel updates. This allows an admin to "install and forget" so to speak. Though you should always periodically check on your server.
Cloudron includes many features beyond just installing apps (apps being the biggest feature here though). Email, DNS Management, Certificate Management, and Backups can all be managed and setup via Cloudron's amazing front-end UI.
Email provided by the Cloudron Server includes basic spam filtering, full text search, user management, alias management, and even quota's. The email service logs to a file, but you can view the log in the front-end as well. Spam filtering uses SpamAssassin and RBL checking with Spamhaus.
The backup solution provided by Cloudron is pretty basic as of this writting. However, it can get the job done for most self-hosting admins out there. It supports Amazon S3, DigitalOcean Spaces, Google Cloud Storage, and more. You can setup a basic schedule, retention policy and even change the storage format as well. Backups also support encryption with a key you must supply (usually a passphrase) as well.
Because Cloudron can host many different apps it offers different database backends as well. MySQL, MongoDB, PostgreSQL are all supported. There is also a basic TURN server, Redis Queue, and SFTP for all the apps to use.
Apps that are packaged for Cloudron must be compatible with Docker (as most servers/services are these days). Packaged apps are still maintained by their original developers. However, Cloudron Devs will update the packages with the apps latest version, changes, etc. These updates are automatically pulled by Cloudron as well. Auto updates can be disabled on a per app basis too.
If there is not an app for the web app you want to host, there is still hope. There are a few developers on the Cloudron Forums that can package the app for you. Myself included. If the app you want is PHP or NodeJS you can almost always just use the LAMP app (See the App Store for details) to install. The LAMP app is a generic Apache/PHP/MySQL setup. It has access to LDAP as well so you can integrate into Cloudron's Login system.
The best way to install Cloudron is via the Installer script. Run the setup and it will walk you through step-by-step to get up and running. Please keep in mind a valid domain is required to setup Cloudron. Cloudron also supports 1-click installs on Amazon, DigitalOcean, Time4VPS, and netcup (as of this writing).
I have been using and developing for Cloudron since 2019. I can honestly say that It's been the simplest solution for my needs. It allows me to host my email, this website, a Matrix server, and more with ease. I rarely have any issues, and when I do have issues the Forum and email support is spot on and responsive.
If you are considering installing Cloudron, get a free month on me using my referal code: d742184850d0165a. If you need a place to host, I currently have been using Kimsufi, but I can also highly recommend DigitalOcean (Referal Link). My DigitalOcean Referal Link gets you $100 in credits over 60 days. Given the resource requirements for Cloudron, I'd recommend DigitalOcean's $15/month or more if you decide to go that route.