I would like to suggest the best company who offer multi Cryptocurrency wallet Development, is Codezeros. They have a trusted team and developer and they will bring your idea into reality with your recommended features. Codezeros Company is providing end-to-end ICO Development Service It will assign best-dedicated team expert.
For me, https://changehero.io/ is the best platform providing exchanging services to your wallet. It's also quite convenient they work with different cryptocurrencies, the operations are also quite easy and fast compared to other platforms.