This leads to an important side issue that people outside the .edu system don't understand, that you release a product for kids that is web based, my daughter's teacher can roll it out to the kids in about 10 minutes using a laser printer to make a QR code of the URL for the kids to scan and then do math drills or whatever, literally during a single recess period. In comparison, if you wrap the same exact content in an app, its going to take at least a year to get the app approved by the technology council and possibly installed, or possibly not if another teacher makes a stronger argument for using the limited storage space for video recording kid presentations of learning or their pet app or who knows, assuming you have the political clout, time, and motivation to ram the new app thru the system.
Educational apps are dead. Educational websites are where its at.
Win a decent MDM, the apps work and work well.