If it still crashes, delete the app and then install it from AppStore again (of course Apple won't charge you again). It helped all the users. To migrate your mobile internet usage stats: before deleting the app, connect your device to computer, open iTunes, go to Programs, and in the bottom list of apps, select Download Meter, select all files and save them to your local computer (they would be about 100kb in size). Once you delete the app and install it again, connect your device to computer, open iTunes, go to Programs, and in the bottom list of apps, select Download Meter, and upload saved files from your computer into the app. This should transfer your data from your previous version of Download Meter.
We are very sorry for this inconvenience!