There are many WordPress App users who are unable to upload their pictures using the WordPress App on iPhone or the Android. It actually does not affect the web or mobile version.
You need to disable the geotagging function inside the app. It is found under your blog settings in the WordPress app. Remember to restart the app after you have done it.
The geotagging will time out as it is unable to found the location in a reasonable time. This time is just a few seconds and you will meet with failed to upload your picture error.