Wolf0 said he need a bigger exchane to sell SPR.
Yeah, we all need a bigger exchange.
I'm working on an API for external miners. I will then make an external CPU miner to test it and as a reference for implementing GPU miner. After that I will start working on GPU miner by myself if there will be no interest from other devs. Even if I will be the first who will make a miner bounty will still remain for improving its hashrate.
I have not much time lately, that's why i am not currently applying for this bounty. As soon as I have some free time, if no one else is working on it, i'll contact you so we can develop the GPU miner. I still need to understand how the signing work, so i can implement it on openCL. (AFAIK you use some external bignum library that we'd need to port to opencl, or at least port the relevant operations).
Also, nvidia cards are much more power efficient for mining X11, so a cuda miner should also be considered. (not my specialty, i'd have to learn how to use cuda, but might be easier to port external libs).