Better not to uninstall preinstalled apps if you intend to reinstall them.

[arubislander]

When some users face intermittent issues with some of the preinstalled apps, a strategy that is often employed when trying to resolve these is to uninstall the app with the aim of reinstalling it, to see if that fixes the issue.

This is inadvisable for several reasons:

• You might face issues trying to reinstall the app.
  While some preinstalled apps are also available in the Open Store, they are treated differently. They are not really uninstalled, but hidden. And often reinstalling the app from the Open Store does not un-hide it. There are posts on the forum on how to get these back, but it is a hassle and requires some command line fiddling.
• It will probably not solve the issue you are experiencing anyhow.
  Almost certainly the issues are caused by (meta)data around the application, rather than the application itself. Uninstalling an application in Ubuntu Touch does not remove the application (meta) data. If this is the goal, then using the Ubuntu Touch Tweak Tool, downloadable from the Open Store, is the best way to go.

The TL;DR; of it is: DO NOT UNINSTALL PREINSTALLED APPS UNLESS YOU NO LONGER INTEND TO USE THEM.

[stanwood]

@arubislander Thank you for this wise advice!

I guess, that in case of trouble, it would be more suitable to use "Ubuntu Touch Tweak Tool" to erase cache and app data, instead of simply uninstall the app as you well explained.

That said, I never experienced any issue with a core app