We have added our new raster2pgsql GUI to our control panel.
The new tool is located in the GIS Tools section of your control panel (see below).
For GeoServer hosting you will find it simpler to load via GeoServer, but for PostGIS Hosting it should come in handy.
You can still invoice raster2pgsql via shell as well.
The tool is currently on our PostgreSQL 9.4 servers but will be added to all servers during the coming week.
Please report any bugs or issues.