There are always lots of "updates" notifications appear on my phone that prompt me to updates the apps I've downloaded. Since all apps i downloaded are "FREE" apps, is it means all the "updates" that prompted are also free and no charge? I just fear that I gotta pay after I "update" it.

Then where did i noe whether they might charge for the updates? Will they mention on the screen? usually the detail will only be what will be updated..