So you don't like plus500. Got it. Lucky I said nothing about them then.
As I have already said, usually each broker has their own platform. Then there are standalone platforms that take in data feeds like NinjaTrader, Multicharts, Tradestation, CQG, TT etc. that you can trade anything on, there's not specific software just to trade gold and silver. All depends on what instrument you want to trade gold/silver with, CFDs, futures or whatever. THEN pick your broker, THEN pick your software.