Looks like Snapper will eventually be ported to other oses.

From:

http://www.20six.co.uk/weblogCategory/w7zy994wfjja?p=1

Are there plans for Snapperfish to venture out to other apps aside from e-mail (in the near future)?
WL: No not really, though we've not said "no" to it. The majority of our team is focused on the next generation of SnapperMail codenamed "Triplex", it keeps us busy. Triplex is a portable cross-platform mail engine that marks the expansion of SnapperMail onto other platforms. We intend to rollout SnapperMail (Triplex) on Symbian UIQ, PocketPC, MS Smartphones and a few more starting next year. We're looking to bring on an additional 4 engineers to maintain the drive onto new platforms. That's not to say Palm OS development will slow, it's still a favorite of ours and we'll continue to push the limits on this platform first. Actually if anyone knows of some local mobile dev talent here in NZ, tell them to check out our jobs page on www.snappermail.com/company/jobs.cfm.