Re “Looking for Boston’s hidden gems? There should be app for that’’ (Editorial, Aug. 7): Hear! Hear! There should definitely be an app that displays public spaces and “privately owned public spaces’’ across Boston.

Keeping tabs on the agreements made with developers as trade for zoning variances or tax incentives should be easy: Just as back-tax liens recorded on houses are disclosed to new buyers and must be satisfied before a property is sold, why not attach these binding agreements so that new owners sign on with eyes open and the public isn’t bilked?

Something like this would have been nice if it applied to TD Garden, which recently made inadequate retroactive payments toward a long-needed, long-promised community athletic facility in Jackson Square, after ignoring a 1993 law requiring the Garden to hold three fund-raisers a year in exchange for state approval to build the new Garden.

Francesca Coltrera

Arlington