i think its not good to mine in smart phone since most of cloud mining uses a lot of power, and using a small devices like smart phones make kill or may destroy your phone. that is my observation doing this kind of staff.
The whole point of cloud mining is to not mine yourself but rent hashing power. So that's why Electroneum doesn't really fit in this thread in my opinion. OP is looking for cloud based mining projects.
I try investing cloudmining in some project that 100% legit to me, it's great to invest in cloud mining if you can't afford some expensive mining rigs. But if you have that money and knowledge to build and run a mining rigs go and try it because you can earn big with your own ways and strategies.