TMS Software has released a new cross platform 3 tier remote database component called TRemoteDB for Delphi XE5 and XE6 Firemonkey. TRemoteDB has a server side Windows application based on http.sys for handling the connections from the clients and talking to the database. The client component works cross platform on Android, IOS, Windows, and OSX. The client server communication takes place via the HTTP protocol. Additionally, it supports SSL from the client to the server and GZIP compression on the datastream. On the client side your existing DataSet components plug directly into the TRemoteDB component and seamlessly enable the 3 tier architecture with limited code changes. TRemoteDB reminds me of DataSnap a lot except that the server is already built. TRemoteDB supports dbExpress, dbGo (ADO), ElevateDB, FireDac, NexusDB, SQL-Direct, and UniDac data access components. According to the info on the features page TRemoteDB was build to scale and built for speed. It is a commercial component but there is a free trial available so you can try it out to see if it works for you.
Head over to check out all of the features of TRemoteDB and download the free trial.