App updates happen all the time
App Updates on the Mothership
Update the apps on your Mothership's iTunes Account regularly (every couple weeks) or right before syncing devices.
App Updates on the Device- I do this only 1 time a year unless there are issues.
App Updates- In a school setting I prefer to update all apps through the Mothership. DO NOT UPDATE ALL APP wirelessly on each device. This way your network is only taxed by 1 set of updates. If done on the iOS device itself your wireless network will likely be brought to it’s knee. It also keeps your Purchase History clean as it only records the update for the Mothership not each individual device. A must when trying to use Purchase History for your App review records and Volume License considerations (more on that later).
Teach your teachers and students to ignore the number in red. Exceptions: App is having issue or it is a seasonal app (example: Cookie Doodle has holiday cookie cutters). For these exceptions teach teachers how to update just that app. A large portion of updates are because of firmware updates and until you decide to update the firmware the apps are fine.