Embarcadero has formally announced IBLite, the free version of IB ToGo for iOS, already shipping in RAD Studio XE4. You can read the announcement at edn.embarcadero.com/article/43128.

As you might know, IBToGo is a DLL-based or in-process version of InterBase, requiring no deployment and giving developers access to the same InterBase GDB files and almost all of the same features of the server version of the RDBMS. Being in-process only an application at a time can use the specific database file, but beside that features are complete and include full transactions support and concurrent access by multiple threads of the same application. Another notable feature IBToGo shares with the full database is strong encryption support. Now this database engine has been available also on iOS: in this case you bind the library to your app executable, given dynamic libraries cannot be used on iOS. Delphi XE4 has full support for this, right in the box. The same library, anyway can also be used to connect to a full InterBase server.

The second part of the announcement, even more relevant, is that there is a new version of this in-process engine called IBLite and currently available only for iOS. This is completely free and can be used in free and commercial apps, with some limitations on database size and the lack on encryption support. Again, this is fully supported in Delphi XE4 for iOS, in the same way of IB ToGo. In fact, there is only one library and you get one behavior or the other depending on the license file you deploy along with the application. Notice, you have to log on Embarcadero web site to ask for that licence file: instructions are in the email with the Delphi or RAD Studio license.

Finally, why do you want to do this, adding extra files to your deployment rather than using the built-in SQLite engine? Beside the fact this is totally up to you, given Delphi for iOS has also full integrated support for SQLite, the advantages are in the file compatibility with InterBase, the extensive feature set, the quality of the SQL engine, and its speed... and the ability to switch to an encrypted database (you don't want to have plain sensitive data on a portable device, do you?) with a license change and no modification in your app code.

Delphi for iOS supports IBToGo and IBLite via dbExpress, FireDAC, and IBX. And you get a free developer license of the InterBase server, now part of the RAD Studio installation.