Oh, wow. Gridcoin... isn't that a scam? Seems like one to me. I don't expect it will be around for long. Be careful with stuff like that. Again, if you don't own the private key, you don't own the coin. I fear a lot of people are going to get burned with that one.
Edit: So sorry, I was confusing this with gladiacoin. IMO, people should stay away from that one.
Come on, are you kidding? Gridcoin has been around since 2013. And BOINC has been around since 2002. (Gridcoin is rewarding BOINC computations). Check Coingecko developer score - Gridcoin is rated 15th, across ALL coins.
For more details, here is a nice summary:
https://steemit.com/gridcoin/@cm-steem/gridcoin-vs-iex-golem-sonm
Ah shoot! I meant gladiacoin which promises to double your Bitcoin in 90 days and looks like a pyramid ponzi scheme. So sorry about that. Will edit my comment. Last thing I want to do is spread FUD.