Source of METAR and TAF

[olorenz]

HI all,
firstly I would like to thank you for such a great app.
I wanted to ask what is the source of METARs and TAFs and how are they getting updated?
We would like to release the app into our EFB iPads around the globe but we need to be sure that only accurate data is provided to our pilots.
Thank you in advance fro your reply.

Regards
Ondrej Lorenz