Hi! I'm co-founder and CEO of GrapheneDB.
We created this service after considering using Neo4j for a client project some years ago and not finding a way to outsource the hosting for it. As a small webdev shop, we had always relied on external services like Heroku, AWS and database hosting services to focus on development.
Neo4j is the leading open source graph database and it can be used from almost any language/framework out there. Graph databases are the best way to deal with highly connected data because they provide index-free adjacency.
For example, if you want to query the friends-of-friends-of-friends-of-friends of a user, other databases will have to query an index and the look-up time will depend on the amount of friendship relationships in the system. The performance gains for these type of queries with Neo4j can be of up to 1000x compared to traditional RDBMS like Mysql.
In a graph database, indexes are basically used to locate the starting point of the query, but the addresses of all neighbors are self-contained in the nodes themselves, making such queries blazing fast, no matter how many relationships there are globally.
Looking forward to get some feedback and take any questions you may have! ;-)
PS: We have a free plan and a Heroku add-on (free plan there too) if you want to play around!
Metabase