There are two different ways to do basic transactions when using ShapeShift.io, our in-app exchange's website, directly.
Quick transactions refer to transactions where the user inputs the receiving address and is given a deposit address from ShapeShift. With this quick order, the user does not need to specify how much of a certain altcoin they want to receive and they can deposit whatever they would like, as long as it is between the maximum and minimum limits. There is no timer to how quickly users have to desposit coins to the deposit address, which can be reused infinite times. The deposit maximum limit is usually lower with quick transactions. The instant rate updates every 10 seconds, and can change during the cause of a transaction.
Precise transactions (also know as specific amount orders) refer to a transaction where the user tells ShapeShift how much they want to deposit BEFORE ShapeShift provides them with a deposit address. Users are prompted with a deposit address and the excact amount specified by the user is expected by ShapeShift. Users can get a better rate with this type of order as well as a higher deposit maximum limit. Users only have 10 minutes to deposit funds to the provided deposit address, which can only be used once. However, the rate is locked in and will not change during the course of an order.
Please consult this article on how to do the same using the integrated Shapeshift Exchange in Coinomi: https://coinomi.freshdesk.com/support/solutions/articles/29000009727-how-can-i-perform-quick-and-precise-exchanges-in-coinomi-
We're hard at work improving our error-messaging and error-handling functionality concerning the in-app exchange.