Sorry but it is my duty to point out that mining on commodity hardware such as CPUs and GPUs is a bad idea. And mining on a phone is an exceptionally bad idea. Saying that it is unprofitable would be a euphemism; even assuming free electricity (and there is no such thing) and that the network difficulty is not going to rise, it would take a phone years just to make 0.01 LTC.
Yes, I know it's generally a bad idea except I've only got 1 asic and about 6 computers. A Raspberry Pi 3 on all 4 cores is about 1/1000 the speed of a Gridseed G-Blade, and runs on about 7 watts. I'm tempted to try to do the GPU assembly language to get their GPUs online to as a 5th thread. These little ARM machines impress me. And a core on a quad core phone is about the same as one of a Raspberry Pi's cores, but it eats battery fast. I've also installed cpuminer under the Debian on my phone, not much difference in performance from Pocket Miner. The alternative is spending more money on dedicated hardware (ASIC) that can't be used for anything else. An ASIC can't be reprogrammed to a different algorithm, cpus and gpus can. SHA256 is built into some of the CPUs
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ddi0514g/way1395175472464.html not that I've managed to make use of it.
What you say is true, but it doesn't change the fact that nowadays mining Litecoin with anything other than an ASIC is unprofitable. If you're not convinced, I invite you to
do the math. At the current price of $28, and assuming you pay 0.06 $/kWh (which is very cheap), in order to be profitable at 7 W you would have to do at least 125 kH/s. You didn't mention your Pi's hash rate, but if my memory serves it should be lower than that by at least one order of magnitude.
Yes, I'm the one who wrote all the assembly code, among other things.
I don't run them just to do hashing, I mostly don't shut them off. Or I'll run cpuminer on one core while I'm doing other stuff. I've mostly used one of my Raspberry Pi 3s for the past several months. It's what I'm using right now to write this. Less power than my Gekko 2pac probably.
Keep in mind that the power draw depends significantly on the CPU load. Even if we assumed that mining would only cause a 2 W extra draw, it would still take at least 40 kH/s to justify it. And even if we somehow managed to achieve such hash rate, it would take 3 months to mine 0.01 LTC, and that's before subtracting the cost of electricity!