@DeathByVisualStudio: Macros in a browser are a bad idea. Do you really want Word macro virii running amok in your browser? Do you want poorly written macros sucking battery and performance from your mobile device?

Aside from that, there are insane technical problems in porting a very specific execution environment and object model to run in a browser and/or on a mobile device.

If data collection is that important, then you need to use an app. Macros are probably the worst possible solution.