Sorry, no. Not something I know about. Main platform I use is steady old Hargreaves Lansdown. They're not the cheapest but I like the interface and they're stable and quite long-established. I also have an account directly with Vanguard UK for some ISA funds.
All depends on your time horizon and your appetite for risk. If you're serious, and want to grow your savings for retirement, that's one thing. How many years out from retirement are you? If you're just gambling, remember that high reward comes with high risk. Warren Buffett said something like...