There are at least a couple low cost or no cost apps that are available for legal research. One that I have used that works well is Fastcase. The app is free and you can also sign up without being charged a fee. But if you want to add more than the most basic features, there will be a charge. A quick look at the Fastcase website shows $695 a year for one membership, and $995 for the most loaded membership. You can also pay by the month.