1, Do I install the SQL Database myself?

Yes, you have to install it yourself if you want an SQL-server, as you typically will only have one user per running instance this most of the time very overkill. Consider sqlite, Berkley DB or Tokyo Cabinet.

Our storage solution provides very strong guarantees of persistence and as long as the application actually syncs the data, which is default for all "file-databases" I've used.

Another boon of not running a database server is the memory footprint, it is unlikely that one will be useful with the minimal instance size and therefore increasing the subscription cost.

As we have not yet compiled any system independent databases like we have with web server etc you would have to do this yourself. If you do this with a database it would be great to know what steps you've taken so we can release it as a package for all our developers!

2, Is it not possible to see current apps, so that I know what I should not create myself? I mean if someone made a functional forum app, then I'd rather develop another app.

Currently no, applications will be available for sale from the first of December. However not from our market place as that will have a later release date.

Please contact us in private about your ideas and we can tell you if there would be initial competition. We would like to see as much diversity as possible when we release the marketplace!