Do you know that Telegram has innovated its own mining system? It is a bot directly connected with their mining farm, creates a real cloud mining interface. This bot gives you a free and upgradable BTC mining speed as promotion. You can join completely free and start mine bitcoin with a 0.003 Bonus for every 12 hours.And again its up to you how much wanted to mine , if you want more you can uprade. You have just install Telegram on your phone and start mining.