Stellar can serve as a backend for a static UI that provides nice exchange features. All you need to build is the UI. Matching, accounts and everything that would normally happen server side can instead be handled by the network.
Advantages:
- You only have to create the UI. You don't need any server side code or a DB.
- Can be set up such that you don't need to have customers or touch funds which should reduce the regulatory burden.
- Can be used by anyone in the world.
- Acts as a decentralized exchange.
- Users can trade using a collection of anchors of their choice. Increasing the liquidity for everyone.
Ideally the UI would be like Poloniex or Oanda or other retail Forex site. Users don't need to have accounts with you.
1) login
Simplest thing here would be to just ask the user to enter their Stellar account secret key. It would never be sent server side. Only used to sign transactions locally.
Inspecting the markets should still be possible without logging in.
2) Allow selecting the pair to trade.
Should have a few preset pairs. But should allow people to enter in Anchors/currency codes.
3) Trusting Anchors
Probably want to have this feature somewhere in the UI. Again with maybe some prest anchors.
4) Trading
This should behave essentially like it does on Poloniex. Or even better on Oanda where you can trade from charts!
After you built this it would be essentially a distributed exchange that anyone could use. A good addition to this would be being an anchor yourself...
For example: https://galactictalk.org/d/27-project-idea-anchoring-digital-currencies