When creating any Transaction in Simplifi, there are a couple things to keep in mind. First, remember that Income (positive) Transactions will be displayed in green, while Expense or negative Transactions are displayed in black:
It's also important to understand that Categories are a great way to differentiate between Income and Expense Transactions. If a Transaction has been assigned an Income Category, it will automatically default to a positive Amount for you; an Expense Category will default to a negative Amount.
If you choose not to Categorize the Transaction, just be sure to enter a + symbol before the Amount to record it as Income: