The Approved Drugs app, which came out on the iTunes AppStore just a few days ago, is about to get its first update, whenever v1.0.1 gets approved. The update deals with the loading performance that currently incurs a bit of a hit when the app first loads, and can overload older devices that have less memory (i.e. crash).
The reason the loading time does/did take awhile is that the data for 1300 drugs with 2D & 3D structures, enumerated tautomers, and various other adjunct data uses up quite a bit of memory, and it needs to be randomly accessible. The XML datasheet format used to store the data is suitable for streaming, but not at all for accessing arbitrary data entries without loading the whole thing into memory. The solution is a little bit inconvenient: invent a custom format for the read-only data that is indexed, so the app can rapidly scan the contents, in any order, without having to parse it all first.
When version 1.0.1 comes out, the content should load up pretty much immediately, and chew up a lot less memory. There is still a delay the first time it calculates fingerprints for a similarity ranking, but it’s still fairly reasonable.