If you are set up as a Company-Admin for your companies Apps (more on roles and User Access Management here) you will see a section in the Left Navigation called Data. From here you can see the list of tags that have been created in Attributes & Tags.
In the data section you can also can select User Devices to view your test users who have behaviour logged from Apps or Websites. Make sure tags is selected as an option in the table by selecting the settings wheel in the top right and selecting TAG HITS if not already selected.
Find your device and click the tag list icon (on the right) for your test device to see the list of tags sent from your device.
On the Tags list screen you will see the list of tags your device has sent complete with any data sent and a timestamp. You can refresh this page periodically to see your tags as you generate them on the app/website side. Note that tags are processed in batches so there may be a delay of up to 1 min between generating the tag and it appearing in the UI.
You can also search your tag list by tag name or the value of data sent using the fields provided, just enter some text and press enter.
And if you delete the user id in the top left and press return you can search all devices: