Does this project aim to let Boinc projects and already involved gridcoin usesrs get tipped in other currencies than GRC, or are there other goals?

Yes, this project will allow BOINC projects and users from BTS/STEEM/GRC/NXT/ETH to tip BOINC users for their completed work.

This could allow us to:

• Distribute GRC from foundation funds across multiple teams at the end of an inter-team competition.
• Distribute user generated assets on the ETH/NXT/BTS platform to BOINC users, albeit this introduces an centralised issuing authority compared to Gridcoin's distributed/decentralized reward mechanism.
• Upvote a STEEM post (to hopefully the front page) and distribute the STEEM funds to BOINC users to that we have more steem power (voting weight) on this website.
• Recruit non-crypto BOINC users to multiple crypto platforms with no investment on their part.