Here is what can be implemented to give Bitcoin Gold edge over other cryptocurrencies:
1. Electrum TOR Wallet
This will add a layer of privacy for the users. Their real IP addresses would not be exposed to the world. This has been implemented by some projects like Groestlcoin, Verge etc.
2. Native miner
Something like One Click miner by Vertcoin team would be a welcome addition. Their miner lets you mine with Nvidia, AMD GPU and even CPU, though the latter is not an efficient way to mine any modern coin.
3. Own Cryptocurrency exchange with BTG as base ticker + fiat gateway
A cryptocurrency exchange with BTG as base ticker and fiat gateway would be amazing.
4. Wirex card support
This would be useful for spending your Bitcoin Gold - just like regular currency. Wirex is most popular cryptocurrency debit card that workd with BTC, LTC and XRP. Bitcoin Gold would be a welcome addition as it is available on almost all cryptocurrency exchanges and has solid liquidity.
5. Android / iOS wallets
Official android and iOS wallets would be great, even though Coinomi on android works like a charm.