Is the Lite version a trial?

No, CashFlowTool Lite is a full functioning cash flow service with features that you can use for free forever.  There are additional features that are part of CashFlowTool Pro that you can try for free for period of time.

When you signup for CashFlowTool Lite, all the Pro features are automatically unlocked so you can try them for free for 7 days. Afterwards, you can unlock CashFlowTool Pro for 24 hours up to 2 more times. 

Learn more here:  https://www.cashflowtool.com/lite#unlock

After you have used all the unlocks, you can either continue to use CashFlowTool Lite for free forever or you can easily purchase a subscription to CashFlowTool Pro.   See the Pro features here:  https://www.cashflowtool.com/pro