After a full day of logging ARRL VHF contest QSOs on my cross-country trip, the iRover iPad app I was using for logging crashed and all of my log data is gone. What a waste! And apologies to those I worked that will not be getting a contest log confirmation or QSL. Beware of Pignology products that are programmed so poorly that they continually crash and lose all stored data.
</rant>
I have found that Hamlog does not fail, and seems to work just fine for portable operations. Took it on a trip to Arizona, and it worked find for three weeks... I also have a review of it at:
http://nk7z.net/review-of-hamlog-by-pignology/