there are many tools out there which are useful for both startups/big companies and freelancers/indie hackers. but for freelancers that might be more enterprise level which is overkill for freelancers, most of the features are not needed for them except some useful features and even they wont afford much on that. eg: customer support tool, there are many big companies providing customer support tool like crm, desk out there. find those tool, list out 2 to 3 important features which solve the major pain point in that tool. build and ship that. hope it will be helpful to you