Not worth to spend any money on it. I bought an X2 multiplier for a month for 4£ but to mine 4£ would take more than a month. So actually you pay 4 pound to get 3 pound. I'd call it simple - cheating the clients. Same with paying for the app itself. It cost so much that you won't get it back in mining. Absolutely useless app. No need to contact the support - the multiplier is just so slow that you pay for using it but you'll never get it back in BTC + you simply loose on it.