Biggest scam. I spent £13 for x5 boost and I mine 21 hours everyday. Its been 15 days now and I earned just £2 sofar. So for 30 days I'll earn only £4-£5 and I'm in loss of £8. Very disappointed and annoyed by cryptotab. Not worth at all. Don't go for boost and you'll atleast be in £2 profit. It's a complete loss in boosts not worth at all. Other applications for mining are much better atleast you can earn a bit more in those.