In case no such app is installed, editing the document is not possible.
{{Attention|The 3rd party app used for editing the file must be able to return the resulting file (in contrast to store it on the file system without telling {{UBIK}})!A recommended app fitting this requirement is the "Photo Editor by Aviary" which is available [[https://play.google.com/store/apps/details?id=com.aviary.android.feather here]].}}
When the editing was finished, the new file is marked as changed and will be committed automatically if Automatic Sync mode is active, else the user can commit manually.