The current version of Nimonik Audit requires iOS 6. We no longer support previous versions of the software.
The easiest solution is for you to completely delete the application from your iPad or iPhone and re-install it. That should resolve the issue.
However, this will delete any data you have collected with the Nimonik Audit app. If you have synced your data to the NimonikApp servers, you will be able to re-download the data. If not, it will be lost.
If you have been backing up your computer regularly with Time Machine or an equivalent system, you can attempt to restore a previous version of the app with your data in it. To do so, please follow the instructions found here.