Hi Guilherme
Good to hear from you. For your questions:
1. The web app is the app that opens on your phone when connecting to the GS-911, it's the web browser, rather than the GS-911 diagnostics app that's only available on a windows machine.
2. Yes, the GS-911 WiFi devices all have a memory card installed for its firmware and data logging, i.e. when you log real time values and save it to the memory card, you can open it and save it at a later stage.
Kind regards and safe travels
Ruan